Pharaoh’s 3,000-year-old sculpture was auctioned in the UK without documents of ownership, Egypt says.

Egypt has asked Interpol, the world’s biggest international police organisation, to help track down a 3,000-year-old sculpture of an Egyptian pharaoh after it was auctioned off to a secret buyer in the United Kingdom last week despite Cairo’s objections.

Christie’s, the Britain-based auction house, sold the 28.5cm brown quartzite bust depicting Tutankhamun, or Tut, for more than 4.7m British pounds ($5.97m).

Egypt’s National Committee for Antiquities Repatriation said in a statement late on Monday that national prosecutors had asked Interpol “to issue a circular to trace” the artefact.

The committee also said it hired a British law firm to file a lawsuit against Christie’s, saying the auction house did not provide documents proving ownership.

It criticised UK authorities for not supporting Egypt’s claim to the sculpture, saying the issue could have an impact on cultural relations, by referencing “the ongoing cooperation between countries in the field of archaeology, especially that there are 18 British archaeological mission working in Egypt”.

Christie’s has denied any wrongdoing, saying it carried out “extensive due diligence” to verify the provenance of the statue and had “gone beyond what is required to assure legal title”.

The auction house added that it had been in touch with Egyptian authorities in Cairo and the London embassy, and that Egypt had never before expressed the same level of concern about an item whose existence has been “well known and exhibited publicly” for many years.

Christie’s has published a chronology of how the relic changed hands between European art deals over the past 50 years. Its oldest attribution places it in the collection of Prince Wilhelm von Thurn und Taxis in modern-day Germany in 1973 – this, however, was disputed by a report from Live Science news site last month, which suggested he had never owned the piece.

In January, Egypt recovered part of a tablet bearing hieroglyphs from a London auction house.

Famous pharaoh

Tutankhamun is thought to have become a pharaoh at the age of nine and to have died about 10 years later. The depiction of the famous pharaoh’s finely chiselled face shows the king taking the form of the ancient Egyptian god Amen.

Slightly damaged at the ears and nose, the sculpture came from the private Resandro Collection of Egyptian art.

Egyptian officials had wanted Thursday’s auction halted and the treasure returned to Egypt.

They had asked the UK Foreign and Commonwealth Office as well as the United Nations cultural body UNESCO to intervene, saying the piece was likely to have been removed from Egypt illegally.

Former antiquities minister and television personality Zahi Hawass told AFP news agency that the piece was thought to have been “stolen” in the 1970s from the Karnak Temple Complex north of Luxor at a time when other artefacts were stolen.

About a dozen protesters waved Egyptian flags and held up signs reading “stop trading in smuggled antiquities” and “Egyptian history is not for sale” outside the British auction house’s London salesroom last week.