Lots Withdrawn from New York Sale

Image from the Becchina archive. Source: Christos Tsirogiannis.

Two lots have been withdrawn from today's sale at Christie's in New York. They are:

1. South Italian black-glossed hydria (lot 36). 
2. Roman marble janiform head (lot 70). 

The hydria had passed through a Sotheby's sale in London and should have alerted informed members of the antiquities trade that it could have been linked to the Medici operation. Were those checks made? And if not, why not?

The full collecting history of the janiform head is unclear.

This leaves the Roman mosaic (lot 9). Why did the Christie's collecting history (so called "provenance") fail to mention the Ariadne Galleries? What is the history of the mosaic prior to its surfacing in the Ariadne Galleries? Why is an image of the mosaic in the Becchina archive? What was the relationship between Becchina and the Ariadne Galleries (and there is evidence of such a link)?

All these identifications have been made by Cambridge-based researcher, Dr Christos Tsirogiannis.

Once again Christie's has demonstrated that its due diligence process lacks the necessary rigour to prevent such material surfacing on the market. Is it time for the Directors of the auction house to put new guidelines in place?