Some of the 2,000 items stolen from the British Museum have already been recovered, George Osborne has said.
The former Chancellor and chair of the museum said police are leading the investigation into how valuable items including jewellery and gems were stolen over a number a years.
But he said some items have already been handed back.
“We’ve started to recover some of the stolen items, which is a silver lining to a dark cloud,” he told Radio 4’s Today programme.
“Some members of the antiquarian community are actively communicating with us in trying to return these items.”
It comes as director of the British Musem Hartwig Fischer resigned over the scandal while deputy director Jonathan Williams stepped back from his role on Friday.
Art dealer Ittai Gradel first alerted the museum that he had spotted items belonging to the museum for sale online in 2021.
The museum carried out an investigation at the time and concluded no items were stolen.
Mr Osborne said that conclusion was “obviously wrong” and the museum will carry out an independent review to establish what went wrong.
The Met Police are now investigating and have interviewed an individual in connection with alleged thefts.
The British Museum has also confirmed that an unnamed member of staff has been sacked.
Mr Osborne denied there had been a ‘cover up’ by museum bosses when the issue first came to light in 2021.
“Hartwig Fisher and Jonathan Williams are honourable people who’ve given their lives to working in the museum sector, I don’t myself believe there was a deliberate cover-up, although the review may find that to be the case,” he said.
“Was there some potential group-think at the time, at the top of the museum, that just couldn’t believe that an insider was stealing things, that couldn’t believe that one of the members of staff was doing this?
“That’s very possible, we wouldn’t be the only institution that has fallen foul of that.”
Confirming his resignation, German art historian Mr Fischer, said the situation facing the London museum was “of the utmost seriousness” and that responsibility for the failure “must ultimately rest with the director”.
The institution said Mr Fischer would step down “with immediate effect”, but later clarified he would step down once an interim leadership arrangement was in place.
A statement from the British Museum later said Williams had agreed to “voluntarily step back” from his duties until the independent review into the thefts had concluded.
The museum said this would happen “with immediate effect”.
In his statement, Mr Fischer admitted the museum “did not respond as comprehensively as it should have in response to warnings in 2021” about the stolen artefacts.
“Over the last few days I have been reviewing in detail the events around the thefts from the British Museum and the investigation into them,” he said.
“It is evident that the British Museum did not respond as comprehensively as it should have in response to the warnings in 2021, and to the problem that has now fully emerged.
“The responsibility for that failure must ultimately rest with the director.”
Mr Osborne said the board of trustees is determined to “fix what has gone wrong.”
“The museum has a mission that lasts across generations,” he added.
“We will learn, restore confidence and deserve to be admired once again.”
The Metropolitan Police said no arrests had been made and it would continue to work “closely” with the British Museum as inquiries continue.