According to Conservation Skills: Judgement, Method, and Decision Making by Chris Caple, there are two reactions a conservator might have when presented with a potentially looted object. He or she may choose to conserve it, thereby ensuring that information about the object, though devoid of archaeological context, becomes available to the public. In an interview for the New York Times, Timothy Potts stressed, “If [the ancient art] goes on view with other like objects, then scholars get to see it and study it; the public gets to come; the claimant, if there is one, gets to know where it is and file a claim.” [...] If a conservator turns away a looted object, however, he or she may be dooming it to obscurity, thereby diminishing the possibility that it will ever be returned.But the issue is not merely sending the object back (repatriation) but that engaging with the illicit antiquities market one is endorsing and providing support for it. Conservation and restoration enhance the value of the object, its marketability.
See Einav Zamir, 'The Conservation Laundering of Illicit Antiquities' Artwatch UK 29 March 2015