LONDON >> The head of trustees at the British Museum said Saturday that the museum has recovered some of the 2,000 items believed to have been stolen by an insider, but admitted that the 264-year-old institution does not have records of everything in its vast collection.

Chairman of trustees George Osborne acknowledged that the museum’s reputation has been damaged by its mishandling of the thefts, which has sparked the resignation of its director and raised questions about security and leadership.

Osborne told the BBC Saturday that 2,000 stolen items was a “very provisional figure” and staff were working to identify everything missing. The items include gold jewelry, gemstones and antiquities as much as 3,500 years old. None had been on public display recently.

He said the museum was working with the antiquarian community and art recovery experts to get the items back.

“We believe we’ve been the victim of thefts over a long period of time and, frankly, more could have been done to prevent them,” he said. “But I promise you this: it is a mess that we are going to clear up.”

Museum director, Hartwig Fischer, announced his resignation on Friday, apologizing for failing to take seriously enough a warning from an art historian that artifacts from its collection were being sold on eBay. Deputy director, Jonathan Williams, also said he would step aside while a review of the incident is conducted.

In early 2021, British-Danish art historian and dealer Ittai Gradel contacted the Museum bosses with his suspicions, but they assured him nothing was amiss. However, at the start of this year, the museum called in London’s Metropolitan Police force.

The museum has fired a member of staff and launched legal action against them, but no arrests have been made.

Gradel told The Associated Press Friday he became suspicious after buying one of three objects a seller had listed on eBay. Gradel traced the two items he didn’t buy to the museum. The object he bought wasn’t listed in the museum’s catalog, but he discovered it had belonged to a man who turned over his entire collection to the museum in 1814.