The number of artifacts believed to have been stolen from the British Museum is about 2,000, the museum's chair of trustees, George Osborne, said on Saturday.

In a scandal that has seen the resignation of director Hatrwig Fischer, the museum had initially said that "items from the collection" had been stolen without giving a specific figure."I will give you an estimate of around 2,000. But I have to say that's a very provisional figure," Osborne said in an interview with BBC radio on Saturday.

"We have started to recover some of the stolen items, which is a silver lining to a dark cloud," Osborne said.

The museum said the missing pieces include gold jewelry, semiprecious gems and glass dating from the 15th century BC to the 19th century AD.

Osborne blames 'groupthink' for security failure

The museum was first alerted to the missing items in 2021, when it was contacted by British-Danish art historian and dealer Ittai Gradel.

Gradel told The Associated Press that he noticed objects for sale on eBay that had reportedly belonged to a collection donated to the museum in 1814. He said he then found the identity of the seller though PayPal, who turned out to be a museum staff member who has since been fired.

According to Gradel, the museum's deputy director said a thorough investigation had found no improprieties and "he basically told me to sod off and mind my own business."

In his resignation statement on Friday, Fischer said the museum "did not respond as comprehensively as it should have in response to the warnings in 2021." He also apologized to Gradel, whom he previously implied had withheld some information.

Chair George Osborne believes that the museum didn't do enough to stop artifact thefts Deutsche Welle

On Saturday, Osborne attributed the museum's failure to act on warnings to "potential groupthink" that "just couldn't believe that an insider was stealing things, couldn't believe that one of the members of staff were doing this."

"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 added.

As a former Conservative finance minister under Prime Minister David Cameron, and later the editor of the influential London Evening Standard newspaper, Osborne is a comparatively high-profile chair of the board of trustees. He was once seen as a potential successor to Cameron, until the 2016 Brexit referendum results led to rapid and far-reaching personnel changes in the Conservative Party.

London's Metropolitan Police said on Thursday that officers had interviewed a man in relation to the reported thefts, and the museum said it was taking legal action against the same individual. No arrests have been made.

British Museum's collections under fire

The British Museum is one of the most famous galleries in the world.

Its collections include the Rosetta Stone, which unlocked the language of ancient Egypt, scrolls bearing 12th-century Chinese poetry and masks created by the Indigenous people of Canada

Critics say many of these items — most notably the Pantheon Marbles from Greece and the Benin Bronzes from Nigeria — were stolen and should be repatriated.

The museum claims that it is protecting the world's cultural heritage.

"We want to tell the British Museum that they cannot anymore say that Greek heritage is more protected in the British Museum," Despina Koutsoumba, head of the Association of Greek Archaeologists, told the BBC after news of the thefts emerged this week.