Egypt has moved to try and halt the sale of a 3000-year-old stone statue of King Tutankhamun, planned to take place at a London auction house next month.
The Egyptian Ministry of Antiquities said on Monday that it was concerned that the artefact had been taken out of the country illegally.
The brown quartzite head of Tutankhamun is expected to fetch more than £4 million (Dh18.64m) when it goes on sale at Christie’s on July 4.
The Egyptian ministry said it had asked the British Foreign Office and the auction house to halt the sale and return the artefact to the country through Egypt’s embassy in London.
“If it’s proven that any piece has been illegally moved out of the country, we will take legal action with Interpol,” the ministry said.
“We will never allow anyone to sell any ancient Egyptian artefact.”
A former Egyptian minister of antiquities said he believed the statue had been taken illegally from an ancient site known as Karnak Temple, in the southern city of Luxor.
"It seems that this sculpture was looted from Karnak Temple," Dr Zahi Hawass told ABC News. "Christie's would not have any proof whatsoever of its ownership."
Christie’s said any accusation that it had procured the artefact illegally was untrue and that the present lot was part of the Resandro Collection, which it described as “one of the world’s most renowned private collections of Egyptian art”.
The auction house said it had acquired the lot, which also includes an Egyptian coffin and bronze Egyptian cat statue, from Munich dealer Heinz Herzer in 1985.
Before this, Joseph Messina, an Austrian dealer, acquired it in 1973-74 from Prinz Wilhelm von Thurn und Taxis who reportedly had it in his collection by the 1960s.
"Ancient objects by their nature cannot be traced over millennia,” Christie’s said. "It is hugely important to establish recent ownership and legal right to sell, which we have clearly done.
"We would not offer for sale any object where there was concern over ownership or export. The work has been widely exhibited and published and we have alerted the Egyptian embassy so they are aware of the sale.
"There is a long-standing and legitimate market for works of art of the ancient world, in which Christie's has participated for generations.
"Christie's strictly adheres to bilateral treaties and international laws with respect to cultural property and patrimony."