– A 3,000-year-old bust of Egypt's boy king Tutankhamen was auctioned off Thursday in London for nearly $6 million, despite claims by the Egyptian government that it was looted and smuggled out of the country.

The sale by the Christie's auction house came a day after Egypt's foreign ministry and its antiquities ministry condemned the company for going ahead with the sale.

They claimed the sale is not valid because the auction house has not been able to verify the ownership of the 11-inch brown quartzite statue of the pharaoh, widely referred to around the world as King Tut.

"There is no ethics here at all," said Zahi Hawass, Egypt's former minister of antiquities affairs, in an interview Friday. "Christie's has no evidence that this head of Tutankhamen left Egypt legally. They did not offer to us any kind of papers to show the legality of this statue.

"This is a black day for Christie's."

He and other Egyptian antiquities officials, including the current minister, are to meet next week to discuss filing a lawsuit to bring back the statue to Egypt, Hawass said.

Christie's said that the statue had never been the subject of an investigation and that it never would have sold it if there were legitimate concerns. Egypt, the company said, did not express concern when the bust was publicly displayed for a number of years or when it was part of a private collection that last sold for $3.7 million in 2016.

Christie's did not release the name of the buyer.

Egypt's demands to have the statue returned to its own prized collection of artifacts from Tutankhamen's tomb come as the country is trying to resuscitate its tourism industry, a significant source of employment and foreign currency.

Egyptian authorities said that the statue was likely stolen during the 1970s from the Karnak temple in the Egyptian city of Luxor, near the tomb of the boy king in the Valley of the Kings. In the early 1980s, Egypt introduced legislation to prevent the removal of ancient artifacts from the country.

Christie's says it is able to track the bust's ownership over the past 50 years, beginning when it was acquired from German aristocrat Prinz Wilhelm von Thurn und Taxis between 1973 and 1974. Egypt says the auction house has not shown documents to prove that.

Tutankhamen became pharaoh at age 9 and ruled until his death at 19, believed to be around 1323 B.C. His remains were excavated in 1922 along with thousands of ancient artifacts, including a gold mask of the boy king, that to this day remains the most significant and well-known archaeological find in Egypt. The collection has traveled to museums in the U.S. and around the world, and it is now in Paris.