Due diligence and the auction houses

We have been talking about "due diligence" and collecting institutions, but what about due diligence and auction houses / galleries / dealers?

The return of the Middle Kingdom duck to Egypt after it had surfaced at Christie's in New York is something to be celebrated. But if Christie's had conducted some research and contacted the Egyptian authorities would they have spotted that the duck had been stolen before Interpol had "got on the case"?

But is this the first time that excavated material has been stolen and resurfaced at Christie's?

Take the Corinth theft. Several pieces stolen from the Archaeological Museum at Corinth popped up at Christie's: "The Property of an American Private Collector". (Three pieces were subsequently bought by Royal Athena Galleries and one was placed in the gallery's sale catalogue.)

Such lots suggest that there is no rigorous process of "due diligence".

And then it struck me. Have members of staff at Christie's (and other dealers and galleries) contacted the Italian authorities to check potential lots against items which feature in the Polaroids from the Geneva Freeport?