An MP has said suspected thefts at the British Museum have exposed the “insulting ridiculousness” of its refusal to return contested artefacts to their country of origin on security grounds. Bell Ribeiro-Addy, the chair of the all-party parliamentary group on Afrikan reparations, believes the 1963 law preventing the return of objects such as the Parthenon marbles and the Benin bronzes should be changed. “One of the most insulting reasons that they’ve given is that the other countries that these items belong to would either not be able to take care of them or they are likely to be stolen,” she said. “But you’ve got people in this country putting them on eBay.” The museum has been at the centre of an escalating storm that on Friday led to the resignation of its director, Hartwig Fischer. It followed the revelation that as many as 2,000 items from the museum collection had been found to be “missing, stolen or damaged” and that police were investigating. Fischer said he accepted responsibility for the museum’s failure to properly respond to warnings in 2021 about the suspected thefts of objects. The museum’s deputy director, Jonathan Williams, has stepped back from his normal duties until an independent review into the suspected thefts has concluded. George Osborne, the former Conservative chancellor who chairs the museum’s board of trustees, said “groupthink” may have prevented leadership from believing that treasures had been taken. He told BBC Radio 4’s Today programme that it was a mess that would be cleared up. “It’s certainly been damaging to the British Museum’s reputation. I think that’s sort of stating the obvious and that’s why I’m apologising on behalf of the museum,” he said. “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.” One “silver lining to a dark cloud”, he said, was that the museum had begun to recover some of the stolen items, which he described as “small items of jewellery, gems, bits of gold that were not on public display”. The turmoil has given fresh momentum to calls for some of the museum’s celebrated and looted objects to be returned to their original homes. Ribeiro-Addy, the Labour MP for Streatham, said: “What makes it more awful is that they’ve been so lax about the [suspected] theft of other people’s items that they haven’t even bothered to assess what it is that they have … to know exactly what’s been stolen.” Osborne said the museum was working with the art loss register and members of the antiquarian community to return missing items. Security has been stepped up around museum storerooms. He said the museum did not have a full catalogue of everything. “Someone with knowledge of what’s not registered has a big advantage in removing some of those items. Obviously, a clear outcome from what has happened is that the British Museum has to accelerate the process that was already under way of getting a complete register of the items in our collection.” Prof Dan Hicks, the author of The Brutish Museums, which examines the looting of the Benin bronzes by British soldiers in the late 19th century, said the suspected thefts should prompt a change in the British Museum’s “imperialist” stance of being the custodian of the world’s heritage. “What we’re seeing [is] another sad incident in the slow-motion car crash of the Victorian model of curation that we’ve seen going on at the British Museum,” said Hicks, the curator of world archaeology at Oxford University’s Pitt Rivers Museum. “That model has to be understood as something which was about a lack of transparency,” he said, arguing that the British Museum and some other UK national museums were still clinging to the imperial nostalgia of having “some God-given entitlement to hold on to these objects and not to tell you about it”. Fischer is staying on until an interim director is appointed, which could reportedly come by the end of this week. A spokesperson said the process was taking place without delay. A British Museum spokesperson said: “We have partnerships with museums and communities around the world and we lend more than 4,000 objects annually. We are dedicated to making our collection accessible to as many people as possible. “We take the care of all the objects in our collection extremely seriously, and thankfully incidents of this kind are incredibly rare. We have already revised relevant security arrangements, and launched an independent review that will make further recommendations to ensure this doesn’t happen again.”