Due Diligence and Auction Houses: the Italian Dimension

Over the last few years there have been several instances from both sides of the Atlantic when auction houses and dealers have offered antiquities for sale that have been identified from images seized in police raids in Switzerland and Greece. The auction houses will no doubt claim, and indeed have claimed, that they have conducted an appropriate due diligence search. Yet it is clear that the procedures followed by the auction houses lack appropriate rigour. They rely on searching databases that will indicate objects stolen from recent collections but not items removed illicitly in recent years from archaeological contexts.

So how can auction houses and dealers avoid offering objects that have surfaced in recent years? Here are three suggestions:
a. Check and authenticate collecting histories (so-called "provenance"). Collecting histories can be fabricated so the paper trail needs to be researched with care.
b. Can the collecting history be traced back to the period prior to the 1970 UNESCO Convention? If not, how can the gap be explained?
c. Contact the relevant authorities in source countries.

I observe that three separate organisations have pressed ahead with sales even when they were aware that there were issues relating to objects. Are those concerns being passed to potential vendors?