Looting Matters: Due Diligence and Auction Houses: the Italian Dimension

David Gill asks on his Looting Matters ('Due Diligence and Auction Houses: the Italian Dimension'):

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?

I assume the phrasing is deliberate, raising an interesting question of long-term responsibility, applicable to all who deal in dugup antiquities. I suppose the next question is the real difference between being "aware of issues", and "not being aware of issues because nobody bothered to ask" and the degree to which, given the nature of the several potential sources of supply of the commodity involved, the latter constitutes culpable professional negligence.