The BBC reports:
Egypt's former antiquities chief, Zahi Hawass, said the bust appeared to have been "stolen" in the 1970s from the Temple of Karnak. "The owners have given false information," he told AFP news agency. "They have not shown any legal papers to prove its ownership."Christie's maintain the history of the piece as follows:
It stated that Germany's Prince Wilhelm von Thurn und Taxis reputedly had it in his collection by the 1960s, and that it was acquired by an Austrian dealer in 1973-4.However the family of von Thurn und Taxis claim that the head was never in that collection [see here].
Christie's reject any hint of criticism:
"Christie's would not and do not sell any work where there isn't clear title of ownership and a thorough understanding of modern provenance."All the auction house needs to do is to present the authenticated documentation showing the sequential history of the head as it passed from collection to gallery. This is all part of the rigorous due diligence process that auction houses are expected to conduct.