Litigation relating to the restitution of cultural property

Published in the Revue de droit international d'Assas (Number 4) in 2021.

The year 2020 marked the fiftieth anniversary of the 1970 UNESCO Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property (hereinafter the "1970 UNESCO Convention"). It provided an opportunity to assess the effectiveness of international cooperation in the field of the restitution of cultural property. Although the second half of the 20th century was characterised by a significant standard-setting activity initiated by international institutions, practice still reveals major difficulties in the application of these legal mechanisms.

Traditionally, "restitution" is understood, either from a public law perspective, as “le rapatriement d’un bien culturel à l’État (ou dans le territoire de l’État) de provenance à la suite d’un pillage ou d’une spoliation à l’occasion d’un conflit armé" (the repatriation of cultural property to the State (or to the territory of the State) of origin following pillage or spoliation in the context of an armed conflict)^[1], or, from a privatist perspective, as “la remise du bien au propriétaire dépossédé à la suite d’une action judiciaire de revendication" (the return of the property to the dispossessed owner following judicial proceedings for recovery)^[2].

In France, while restitution generated a substantial body of scholarship since the 1970s - first as a result of the preparatory work for the 1970 UNESCO Convention, and later following the renewed attention in the 1990s to property spoliated from Jewish families during Second World War - two recent developments have, over the past ten years, brought into sharp relief new issues raised by the restitution of cultural property.

First, the international community had to respond to the large-scale destruction and looting perpetrated by the Islamic State by adopting two UN resolutions in 2015 and 2017^[3] to combat the trafficking of Near Eastern antiquities and to organise the return of those objects. France committed itself through Cinquante propositions françaises pour protéger le patrimoine de l’humanité (Fifty French proposals to protect the world's heritage)^[4] which precede the Loi du 7 July 2016 relative à la liberté de la création, à l’architecture et au patrimoine‍^[5]. That law introduced additional domestic measures to facilitate the interception and restitution of all Iraqi and Syrian cultural property likely to have been unlawfully traded on French territory^[6].

While those measures mainly concern cultural property held in private hands, it was the issue of the restitution of African cultural property in French museums that was raised by President Emmanuel Macron in his speech at the University of Ouagadougou (Burkina Faso) on 28 November, 2017. In its wake, the report by Felwine Sarr and Bénédicte Savoy set out concrete legal proposals to enable the restitution of such cultural objects “sans pour autant remettre en cause le principe général d’inaliénabilité des objets culturels propriétés publiques – principe fondateur de la législation des musées de France" (without calling into question the general principle of inalienability of cultural objects belonging to the public domain — a founding principle of museum legislation in France)^[7]. The Commision de la culture du Sénat, tasked with examining the possibility of enacting a framework statute for the declassification of disputed objects, underscored the difficulty of “concilier des objectifs contradictoires, à savoir faciliter le droit de chacun à avoir accès, dans son pays, à son propre patrimoine et au patrimoine commun de l'humanité sans obérer les capacités de nos propres musées à remplir leurs missions" (reconciling contradictory objectives, namely to facilitate the right of everyone to have access, in their country, to their own heritage and to the common heritage of mankind without interfering with the capacities of our own museums to fulfill their missions)^[8].

This restitution debate, which questions our relationship to ownership of works of art and the legitimacy of universal museums^[9], crystallises societal issues that often precede legal solutions that may be slow to emerge. To grasp the substance of these debates, it is necessary to return to the foundations of the legal obligation of restitution, before analysing the incorporation of these international commitments into European Union law and into domestic legal systems, notably through the concept of due diligence, which has become a rallying point in the implementation of restitution.

I. Fragmentation of the law governing the restitution of cultural property

While the obligation to restitute is grounded in international law, its implementation depends on the willingness of States Parties to agree on harmonising their domestic legislation. In part to address these divergences, it has been necessary to multiply the means of dispute resolution in this field.

A. Legal foundations and developments concerning the nature of the obligation to return in international law

The obligation of restitution should be viewed as an aspect of international cooperation for the protection of cultural heritage. In practice, it supports the application of principles prohibiting destruction, theft and illicit export of cultural property.

The protection of cultural property was initially considered in the context of armed conflicts (even if, as we shall see, it is no longer confined to that context). While certain provisions referred to it in peace treaties concluded before the nineteenth century^[10], the first milestones of international law were laid by the Hague Codification Conventions of 1899^[11] and 1907 on the Laws and Customs of War on Land^[12]. For the first time in international law, they articulated a principle prohibiting the confiscation of works of art and other cultural property during armed conflicts^[13]. That prohibition entails an obligation of reparation, which may take the form of restitution or compensation.

After the First World War, the Treaty of Versailles of 1919^[14] organised the restitution and compensation of property stolen or destroyed during the conflict. Where possible, the restitution of movable property was then associated with the sanction imposed on the defeated State^[15].

The restitution of property spoliated during the Second World War was, for its part, addressed through specific non-binding bilateral instruments (soft law). The London declaration of 1943, considers as invalid any transfer of property rights made during the conflict, including those concerning cultural property^[16]. Later, the 1998 Washington conference^[17] , convened to address difficulties in applying international conventions, encouraged signatory States to pool resources to document the provenance of works confiscated by the Nazis in order to facilitate their restitution.

It was not until the 1954 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict and its two Protocols, adopted on 14 May 1954, that an explicit obligation of restitution appeared in international law. G. Carducci proposes a three-part reading of the obligations set out in the 1954 Hague Convention^[18]. First, States must ensure the material protection of cultural property^[19] (by avoiding intentional destruction, bombardments and other attacks referred to in the First Protocol). Second, they are subject to an obligation of non-removal, embodied in the prohibition on exporting cultural property from its territory of origin during the conflict^[20]. Finally, where the first two obligations have not been respected, the Convention establishes an obligation to restitute cultural property:

Each of the High Contracting Parties undertakes to return, at the close of hostilities, to the competent authorities of the territory previously occupied, cultural property which is in its territory, if such property has been exported in violation of the principle set forth in the first paragraph. Such property shall never be retained as war reparations.^[21].

These three components may be seen as interdependent: the return of stolen or unlawfully exported property is conditioned on the existence of protective national and international legislation that prevents destruction and regulates circulation; conversely, the prohibition of pillage and illicit export (in violation of the law of the country of origin) is deprived of substance if it does not provide for restitution as a sanction for breach of protective rules.

While these rules enabled the restitution of unlawfully acquired property in wartime, they did not yet have universal scope. In 1970, UNESCO embraced the concept of an obligation of restitution in a context not linked to armed conflict through the UNESCO Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property. The Convention seeks to harmonise Member States’ heritage-protection measures in order to foster international cooperation. Article 13 thus provides a diplomatic request mechanism enabling the State of origin to seek the return of an object falling within the category of “cultural property” as defined by Article 1 of the 1970 UNESCO Convention.

However, because the 1970 Convention is not retroactive, it applies only to property stolen, looted or unlawfully exported after its entry into force. Moreover, in order to produce effects domestically, it must be ratified and implemented through national legislation, including the possibility of an action for recovery of stolen or lost cultural property brought by, or on behalf of, the lawful owner^[22].

It is therefore not possible to base court proceedings directly on the principles of the 1970 UNESCO Convention.^[23], as recalled by the Cour administrative d'appel, in Federal Republic of Nigeria c/ de Montbrison of April 5, 2004^[24]:

La revendication des statuettes litigieuses n’est pas fondée dès lors que la saisie a été pratiquée sur le fondement de la Convention de Paris du 14 novembre 1970 ratifiée par la France le 7 avril 1997, concernant la lutte contre l’exportation illicite de biens culturels. Les dispositions de cette convention ne sont pas directement applicables dans l’ordre juridique interne des États parties et ne créent aucune obligation directe pour les ressortissants.

(The claim for the contested statuettes is unfounded, since the seizure was carried out on the basis of the Paris Convention of 14 November 1970, ratified by France on 7 April 1997, concerning the fight against the illicit export of cultural property. The provisions of that Convention are not directly applicable within the domestic legal order of States Parties and create no direct obligations for individuals.)

In the absence of directly applicable rules of international law, differences in regimes for the protection of cultural property have widened between States. To address this, the UNIDROIT Convention on Stolen or Illicitly Exported Cultural Objects (hereinafter the “1995 UNIDROIT Convention”) was signed in Rome on 24 June 1995 at the initiative of France and Italy. Intended to strengthen the 1970 UNESCO Convention in combating trafficking in cultural property, it has not to date been ratified by France.

It is important to emphasise the political dimension of heritage protection: States’ more or less liberal approaches directly influence the degree of regulatory constraint and, a fortiori, the possibilities for restitution. Accordingly, the nature of the obligation of restitution depends closely on how each State defines its national heritage (national treasures) and on the thresholds of value and age it establishes to identify cultural property. The scope of application of international conventions protecting cultural property therefore varies considerably across domestic legal systems.

The lack of harmonisation of national legislation concerning the determination of protected cultural property necessarily entails a lack of harmonisation concerning restitution or return of the property in question. M.H. Carl speaks of fragmentation of the restitution system^[25], where a universal rule would be required to harmonise legal responses regardless of the nature of the property.

This fragmentation increasingly encourages recourse to alternatives to restitution, such as long-term loans, repurchase by an individual for the purpose of restitution ^[26] or inter-State agreements^[27] .  In practice, extrajudicial avenues are multiplying, with treaty law—preceding customary international law, taking up the issue.

B. The multiplication of dispute-resolution mechanisms

The obligation of restitution is grounded in the determination of illegitimate ownership. Restitution concerns both stolen property and property unlawfully exported from its territory of origin, in violation of national and international rules protecting cultural property. Traditionally, disputes may be resolved through contentious proceedings, a judicial action, or through a consensual approach following negotiation between the parties^[28].

Contentious dispute resolution relies on private international law. Depending on prevailing doctrinal approaches and the relationship between domestic and international law, States may favour either the lex rei sitae (the law of the place where the object is situated) or the lex originis (the law of the object’s place of origin). Where French courts are seised, they apply French conflict-of-laws rules, namely the lex rei sitae, i.e., the law of the place where the disputed object is located. Thus, if the work is located in France, the lex rei sitae designates French law. The doctrinal debate on the applicable law highlights the limits of international cooperation between so-called “market” States and so-called “source” States. Because application of the law of origin (lex originis) is often favourable to the requesting State^[29], il semble que les pays liés au marché de l’art craignent que son application entraîne un volume important de requêtes et fasse obstacle au commerce d’antiquités (it seems that countries linked to the art market fear that its application will lead to a large volume of requests and hinder the antique trade)^[30].

Where a restitution claim is brought by an EU Member State—or one of its nationals—against another Member State, the Code du Patrimoine has, since a 2015 statute^[31] provided a procedure for the return of cultural property. Once an object is identified as a national treasure within the meaning of Article 36 of the Treaty on the Functioning of the European Union, and it has unlawfully left the territory of a Member State^[32], the requesting State may bring an action for its return before the competent court of the Member State in whose territory the object is located^[33]. Where French national treasures are located in another Member State and have been stolen or unlawfully removed from French territory, it is for the Minister of Culture to initiate proceedings seeking restitution^[34].

However, the law struggles to address works stolen or unlawfully displaced before the adoption of international norms, which, as noted, have no retroactive effect.

Moreover, in addition to the many disadvantages of judicial avenues (limitation periods, cost and slowness of proceedings, loss of confidentiality, etc.), French law faces a difficulty stemming from a principle protecting national heritage: the inalienability of French public collections. French public collections are inalienable and therefore cannot be transferred gratuitously or for consideration.^[35]. Since the Loi du 4 janvier 2002 sur les Musées de France, declassification has been possible, subject to the binding opinion of the National Scientific Commission on Collections (CSNC), only where the object has “perdu son intérêt public à figurer dans les collections" (lost its public interest in remaining in the collections). The Loi d’accélération et de simplification de l’action publique^[36]provides, in Article 13, for the abolition of that Commission, without calling into question the possibility of declassification, now subject to the High Council of the Musées de France^[37]. In addition, Article L451-7 of the Code du Patrimoine provides that objects incorporated into public collections by gifts or bequests, or acquired with State assistance, cannot be declassified, thereby closing this avenue for the vast majority of objects held in public collections. Parliamentary intervention through ad hoc statutes, such as the Loi du 24 décembre 2020 relative à la restitution de biens culturels à la République du Bénin et à la République du Sénégal^[38], s therefore essential to create exceptions to the principle of inalienability. That principle had already justified, in 2002 and 2010, the adoption of two ad hoc statutes allowing the return of human remains to their countries of origin^[39] . In light of the complexity of implementing this rule, new extrajudicial pathways have emerged to organise the return of certain objects to their countries of origin.

Marie Cornu proposes two alternative techniques for the return of works ^[40] : First, upstream, the State may refrain from acquiring a work whose history is insufficiently known and, where theft or looting is suspected, report it. This non-binding approach relies on museum ethics^[41]. Second, Marie Cornu supports mediation and arbitration procedures leading to the loan or deposit of works where legal transactions are complicated either by the passage of time between acquisition and the restitution request, or because the disputed object is inalienable^[42].This was the case for Korean manuscripts from the Joseon dynasty, whose return was organised following lengthy negotiations between France and Korea. As France did not wish to relinquish ownership of archives considered national treasures, it was agreed to grant a “long-term deposit” in the form of a five-year loan, renewable indefinitely^[43].

Should one therefore distinguish “return” from “restitution”? “Return”, which does not necessarily entail a change of ownership, may be understood as repatriation following a lawful exchange or where the removal occurred before the entry into force of international norms^[44], typically through a consensual process. The doctrinal debate distinguishing restitution, return, transfer and repatriation reflects the politicised use of these terms. Yet in all cases the underlying issue is the same: restoring property to its legitimate owner, because current ownership is rooted in an unlawful or morally reprehensible act of appropriation (sale under constraint, vitiated consent, etc.).

The law of restitution, while grounded in the international conventions that gave rise to it, is constantly evolving and must respond to growing social challenges. Thus, the solution adopted for the return of the Korean manuscripts in 2012 - an indefinitely renewable loan - was not replicated for the property restituted to Benin and Senegal in 2020, which instead involved a transfer of ownership. That restitution gave concrete effect to the political will expressed by President Emmanuel Macron and was implemented through a declassification statute adopted by Parliament^[45].

The trial-and-error process and the evolution of international law on restitution reflect the difficult balance between safeguarding cultural heritage and ensuring the free movement of goods. To understand the foundations of the obligation of restitution, Manlio Frigo argues that one should "privilégier la recherche de l’intérêt juridiquement protégé par les règles de droit international concernées " (give priority to identifying the interest legally protected by the relevant rules of international law)^[46]. In his view, the primary objective is “à la protection des biens culturels en tant qu’expression d’un patrimoine auquel ils appartiennent et pour lesquels ils revêtent une importance qualifiée" (the protection of cultural property as an expression of the heritage to which it belongs and for which it has particular significance)^[47]. Achieving that objective is complicated by the lack of harmonised national legislation on restitution, such that today the notion of due diligence, derived from international law, increasingly appears as a unifying solution.

II. Convergence around the concept of due diligence

The notion of due diligence, derived from international law, appears to provide common ground capable of offsetting the lack of harmonisation between domestic legal systems. While its incorporation into EU law and into several national legal systems is a genuine step forward, it can only develop in parallel with the expansion of provenance research.

A. The rise of the concept of due diligence in support of the determination of good faith

Article 7 of the 1970 UNESCO Convention sets out fundamental provisions on the restitution of cultural property. It provides:

The States Parties to this Convention undertake: […] (ii) to take appropriate steps to recover and return, at the request of the State Party of origin, any such cultural property stolen and imported after the entry into force of this Convention in both States concerned, provided that the requesting State shall pay just compensation to an innocent purchaser or to a person who has valid title to that property.

However, given the divergences among Member States’ legal systems regarding the definition of good faith and the effects attached to it, the notion of “just compensation to an innocent purchaser or to a person who has valid title to that property” (Article 7(b)(ii)) raised many questions and fuelled concerns about abusive compensation claims.

In 1995, the UNIDROIT Convention, still not ratified by France, introduced a notion drawn from Anglo-American business law^[48] : due diligence, a requirement of a purchaser regarding what is being acquired.

Due diligence has the advantage of being more objective than good faith: rather than enquiring into the possessor’s belief at the time of acquisition, it focuses on conduct. As an additional guarantee of objectivity, the criteria for assessing that conduct are expressly set out in Article 4(4) of the UNIDROIT Convention:

In determining whether the possessor exercised due diligence, regard shall be had to all the circumstances of the acquisition, including the character of the parties, the price paid, whether the possessor consulted any reasonably accessible register of stolen cultural objects, and any other relevant information and documentation which the possessor could reasonably have obtained, and whether the possessor consulted accessible agencies or took any other steps which a reasonable person would have taken in the circumstances.

The operational nature of the concept quickly proved attractive, and it did not remain confined to UNIDROIT: it spread into EU law, notably through Directive 2014/60/EU of the European Parliament and of the Council of 15 May 2014 on the return of cultural objects unlawfully removed from the territory of a Member State^[49], and into domestic legal systems. UNESCO ultimately adopted the concept in its Operational Guidelines for the implementation of the 1970 Convention, which encourage States Parties to use the UNIDROIT concept of due diligence^[50].

In French law, the transposition of the 15 May 2014 Directive led to the incorporation of the UNIDROIT term “due diligence” (diligence requise) into national legislation. In the event of restitution, Article L112-8 of the Code du Patrimoine makes compensation payable only to a good-faith possessor who exercised due diligence when acquiring the property; the provision even reproduces verbatim the steps listed in Article 4(4) of the UNIDROIT Convention.

A further step was taken when due diligence ceased to be limited to assessing whether compensation should be paid to a good-faith possessor in the context of restitution, and became a general criterion to be taken into account in any transaction involving cultural property.

Thus, under the provisions of article L111-3-1 paragraph 3 of the Code du Patrimoine^[51] :

‍La demande [de certificat d’exportation] ne peut être déclarée irrecevable lorsque le demandeur apporte la preuve qu'il a exercé la diligence requise, au sens du troisième alinéa de l'article L. 112-8, au moment de l'acquisition et que le délai dont dispose le propriétaire d'origine ou toute autre personne fondée à agir en revendication du bien ou en nullité de l'acte de cession du bien est expiré.

(The application [for an export certificate] may not be declared inadmissible where the applicant provides evidence that he exercised due diligence, within the meaning of the third paragraph of Article L112-8, at the time of acquisition, and that the limitation period available to the original owner, or to any other person entitled to bring an action for recovery of the property or for annulment of the transfer, has expired.)

The introduction of due diligence into French law has tempered the scope of the well-known maxim in Article 2276 of the Civil Code: en fait de meubles, la possession vaut titre (“possession is equivalent to title in respect of movables”). Although it is traditionally taught that this provision creates a presumption of ownership in favour of the possessor - so that, in an ownership claim, the burden of proof lies on the claimant rather than the possessor - requiring the possessor to prove that due diligence was exercised at the time of acquisition undermines that presumption. The burden of proof is thereby shifted from the claimant to the possessor, who must demonstrate the steps taken when acquiring the cultural object. This requirement also affects the second paragraph of Article 2276, which provides that “celui qui a perdu ou auquel il a été volé une chose peut la revendiquer pendant trois ans à compter du jour de la perte ou du vol, contre celui dans les mains duquel il la trouve" (a person who has lost an object or from whom it has been stolen may recover it within three years from the day of the loss or theft, from the person in whose possession it is found). Because that three-year limitation can be invoked against the claimant only by a good-faith possessor^[52], making good faith dependent on proof of due diligence effectively allows the original owner to recover the property even after three years where the possessor cannot demonstrate that such steps were taken.

More explicitly, Swiss legislation introduced, in the Federal Act on the International Transfer of Cultural Property of 20 June 2003, an Article 16 on the “duty of care”^[53]. Under that provision, art dealers and auctioneers must establish the seller’s identity, inform clients of the import and export rules in force in the States Parties, keep a register of acquisitions of cultural property—the Swiss equivalent of the French livre de police^[54] - and “fournir au service spécialisé tous les renseignements nécessaires concernant l’accomplissement de ce devoir de diligence" (provide the specialised authority with all necessary information concerning the fulfilment of this duty of care^[55].

Similarly, Germany’s Kulturgutschutzgesetz of 31 July 2016^[56] establishes a two-tier due diligence regime distinguishing private individuals from art-market professionals, as do the Netherlands in Article 87a of their Dutch Implementation Act for the 1970 UNESCO Convention^[57].

Case law, particularly Swiss, Belgian^[58] and Spanish^[59], also increasingly scrutinises the conduct of an acquirer of cultural property claiming to have acted in good faith. The Swiss Federal Supreme Court has thus held:

[…] qu'un collectionneur d'art n'avait pas respecté son devoir de diligence (fondé sur la définition de la bonne foi de l’art. 3 du Code civil) lors de l'acquisition d'un tableau de Kasimir Malevitch, dont il s’est avéré qu’il avait été volé, car il avait ignoré une « rumeur » qui lui avait été rapportée par l’experte qui avait examiné le tableau en vue de déterminer s’il était authentique, rumeur selon laquelle un tableau de Malevitch avait été volé et se trouvait sur le marché en Europe.

([...]an art collector failed to comply with his duty of care (based on the concept of good faith under Article 3 of the Civil Code) when acquiring a painting by Kazimir Malevich, later shown to have been stolen, because he disregarded a “rumour” relayed by the expert who examined the work for authenticity, namely, that a Malevich painting had been stolen and was circulating on the European market)^[60].

Beyond this normative and case-law framework, due diligence is also central to an ethical framework based on professional self-regulation. A number of international codes of ethics refer to due diligence, including the International Council of Museums (ICOM) Code of Ethics for Museums, the UNESCO International Code of Ethics for Dealers in Cultural Property, and the Code of Ethics in the Charter of the International Confederation of Art Dealers (CINOA).

The ICOM Code of Ethics places particular emphasis on due diligence, stressing that it is not limited to transactions between private individuals. Under Article 2.3, entitled “Provenance and Due Diligence”, of the ICOM Code of Ethics:

Every effort must be made before acquisition to ensure that any object or specimen offered for purchase, gift, loan, bequest, or exchange has not been illegally obtained in, or exported from its country of origin orany intermediate country in which it migh thave been owned legally (including themuseum’s own country). Due diligence in this regard should establish the full history of the item since discovery or production.

Although initially conceived strictly as a factor for determining whether compensation should be paid to a good-faith possessor in the context of restitution, due diligence, applicable to private collectors, dealers and museums alike, has thus become “un outil essentiel de la lutte contre le trafic illicite de biens culturels” (an essential tool in the fight against illicit trafficking in cultural property) ^[61] in the words of the Subsidiary Committee of the Meeting of the States Parties to the 1970 UNESCO Convention, which met in 2019 for its seventh session.

B. The inevitable development of provenance research

Provenance research is intrinsically linked to due diligence, since it aims to reconstruct the history and trajectory of a cultural asset from its creation or discovery to its current location. Conducting provenance research prior to acquiring cultural property therefore amounts, in principle, to exercising due diligence.

With the rise of illicit trafficking in cultural property, both private and public institutions have developed a range of tools for art-market actors to facilitate provenance research in order to curb this illicit trade.

A pioneer in the field, the British company Art Loss Register has established a database - currently listing more than 700,000 lost, stolen or looted art objects - based on reports from victims of looting or theft, insurers, police forces and others. It is now common practice for the seller, or more frequently the professional intermediary, to request from the Art Loss Register the production of a certificate attesting that the work is not recorded in the database before offering it on the market.

In 2020, Interpol also launched a free mobile application, ID-Art, which facilitates access to its database of stolen works of art. It contains approximately 50,000 photographs and descriptions of stolen and missing cultural property, provided to Interpol by national services and authorised international bodies. The app allows users to search either manually by entering the object’s characteristics (type, technique, material, description, title, artist, format, condition and location of the signature, etc.), or visually by taking a photograph of the cultural object, to check whether it appears in the database.

The Central Office for Combating Trafficking in Cultural Property (OCBC), which forms part of the French criminal police, also maintains a database, TREIMA, which records all complaints relating to cultural property. Although TREIMA is accessible only internally to OCBC staff, it is possible to submit a request for consultation concerning a specific object.

However, while these databases are essential tools for art-market actors, their scope remains limited: a negative result does not mean that the object was not stolen, illicitly excavated or unlawfully exported. It may simply not yet have been reported stolen, or it may be “undiscovered”^[62] as in the case with objects looted from archaeological sites.

In addition to these databases, ICOM produces Red Lists identifying categories of cultural property at risk by world region^[63]. Unlike the databases mentioned above, these Red Lists are not lists of stolen objects; they simply help identify categories of objects particularly exposed to trafficking.

Networks are also developing, such as the ARCHEO database of the World Customs Organization (WCO), which aim to facilitate the exchange of information between professionals and experts in the protection of cultural heritage thereby optimising effective law enforcement in this field.

Such networks could also facilitate exchanges between the art market and heritage-protection actors. As witnesses to the circulation of objects, dealers are an essential link in identifying works of doubtful provenance. Cooperation between dealers and institutional actors would enable the former to avoid acquiring objects with unsatisfactory provenance and allow the latter to locate more cultural property stemming from illicit trafficking. To facilitate this dialogue, it would be beneficial to systematise recourse to a UNESCO standard , Object ID, designed to simplify and standardise the description of art and antiquities. The Object ID record could be secured through a blockchain system to prevent falsification of data.

Nevertheless, provenance research pursues objectives far broader than combating illicit trafficking in cultural property. By reconstructing as accurately as possible the path and history of an object from its creation or discovery to its current location, provenance research makes it possible not only to ensure that the object has not been unlawfully exported or stolen, but also to verify that it is not a forgery, and that it was not spoliated during the Second World War or during colonial contexts. Cases involving forgeries, such as the Wolfgang Beltracchi affair, theRuffini afffair^[64], the Versailles Fake affair^[65], as well as claims by victims of spoliation, whether Jewish families dispossessed during the Second World War or African States looted during colonial periods, occupy a prominent place in current events.

In response to these claims, museums have stepped up provenance research on objects in their collections. In France, an order of 16 April 2019 created a Mission de recherche et de restitution des biens culturels spoliés entre 1933 et 1945 (Mission for Research and Restitution of Cultural Property Spoliated between 1933 and 1945)^[66].In particular, it seeks to identify the owners of the Musées Nationaux Récupération (MNR) - works recovered in Germany after the Second World War and still held on deposit in French museums because their lawful owners have not been identified In Germany, the German Museum Association published in 2018 a Guidelines for the Care of Collections from Colonial Contexts^[67], and the German Federal Foreign Office recently announced that Germany was moving towards the restitution of all bronzes looted in Benin (present-day Nigeria) held in its public collections^[68].

Such provenance research requires consultation of a very large number of public archives (analysis of catalogues and auction records, etc.) as well as private archives (correspondence, wills, private inventories, photographs, etc.), with varying degrees of accessibility - inevitably involving significant time and financial investment^[69].  Ideally, provenance research should be carried out for all cultural property involved in transactions and for a substantial portion of cultural property displayed in museums.

In light of this, training for the profession of provenance researcher is becoming a priority, which cannot be achieved without building the discipline of provenance research itself. Such work could begin with an in-depth scholarly reflection on what “provenance” means in relation to cultural property, from the perspectives of art history, history, law and anthropology. On the basis of these firmly established academic foundations, it will then be possible to develop a typology, a methodology and tools (databases, networks for communication between researchers, etc.) that will constitute a common baseline for provenance research. Only properly trained provenance researchers equipped with appropriate methods and tools will be able to meet the growing demand for provenance research on cultural property.