Like all D.C. museums, the private Museum of the Bible has been temporarily closed for months, in adherence with the mayor’s stay-at-home order for the coronavirus pandemic. And yet, even with its doors closed, the museum finds itself involved in a major legal case surrounding a prominent artifact it briefly displayed.

On Monday, federal prosecutors in the Eastern District of New York filed a civil action to forfeit a clay tablet, formerly housed at the Bible museum, called the “Gilgamesh Dream Tablet.” The tablet contains a portion of the “Epic of Gilgamesh,” an epic poem written in cuneiform, the ancient Mesopotamian writing system, and one of the oldest pieces of literature in the world.

Hobby Lobby, the arts-and-crafts company behind the Bible museum, bought the rare piece for $1.6 million in 2014 from an international auction house, which failed to disclose the tablet’s true origins, prosecutors say. U.S. Department of Homeland Security investigators discovered that the piece was stolen from Iraq and sold to an unidentified U.S. antiquities dealer in 2003—not “well before” 1981, as the auction house had told Hobby Lobby.

The tablet was sold again, in 2007, with a false provenance letter that traveled with it from owner to owner and was given to the auction house, according to court documents.

Despite the Bible museum’s and Hobby Lobby’s inquiries, the auction house didn’t reveal the truth about the object’s origins, the complaint says. Homeland Security agents seized the 6-by-5-inch tablet from the museum last September, and now, the U.S. is seeking to return it to Iraq. (The tablet was displayed at the museum for a short time before its false provenance came to light.)