The United States will formally return an illegally imported 3,500-year-old tablet recounting the epic of Gilgamesh to Iraq on Thursday, announced the Unesco. The piece is believed to have been stolen from an Iraqi museum in 1991, before being smuggled onto the American art market in 2007.

The ancient tablet, which a wealthy US collector had acquired along with other Iraqi artefacts to display in the Washington Museum of the Bible, will be handed over to Iraqi officials at the Smithsonian Insтιтution on 23 September.

This clay tablet with Akkadian cuneiform characters is believed to have been stolen from an Iraqi museum in 1991, when the country was embroiled in the first Gulf War.

The precious archaeological piece, one of the oldest literary works, was then “smuggled onto the American art market in 2007”, according to Unesco.

The rare fragment, which recounts a dream sequence from the Gilgamesh epic, is one of many ancient artifacts from Iraq and the Middle East collected by David Green, the billionaire owner of the Hobby Lobby craft store chain.

It was seized by the US Justice Department in 2019, two years after Green opened the museum dedicated to ancient Christian history in downtown Washington.

Audrey Azoulay, director general of the Unesco called the repatriation of the tablet, along with 17,000 other artefacts sent back to Iraq in July, “a significant victory in the fight against the illicit trafficking of cultural objects.”

“The theft and illicit trafficking of ancient artefacts continues to be a key funding source for terrorist groups and other organised criminal organisations,” said the Paris-based agency.

It adds that when the Islamic State armed group controlled large parts of Iraq and Syria over 2014-2019, Iraqi archaeological sites and museums were systematically looted.