The British Museum said items from its collection were found to be ‘missing, stolen or damaged’ (Tim Ireland/PA)

The chairman of the British Museum All-Party Parliamentary Group has accused Greece of “blatant opportunism” in claiming the institution is “not safe” following thefts from the museum.

The British Museum announced last week that items from its collection were found to be “missing, stolen or damaged” and police are investigating.

Legal action is being taken by the museum against an unnamed member of staff, who has been sacked.

Tim Loughton told BBC Radio 4’s Today programme that news of items going missing from the museum’s collection in London is “damaging” but the institution is taking the thefts “seriously”.

The MP, who has been in touch with the museum, added: “For reassurance, people want to know the extent of the objects which have disappeared, what investigations took place at the time when various reports came in and what is being done now because otherwise (it’s) getting out of hand.”

The museum has not specified how many items have been stolen or detailed what the missing items are, saying only that they were “small pieces” including “gold jewellery and gems of semi-precious stones and glass dating from the 15th century BC to the 19th century AD”.

The Times has reported that the thefts happened over at least two decades.

Mr Loughton said: “What is particularly damaging is (the) blatant opportunism of the Greeks and others saying ‘Oh no, the British Museum is not safe…’ It’s incredibly rare that things go missing.”

Greece has been campaigning for decades for the return of the Parthenon Sculptures, which once adorned the Parthenon atop the Acropolis in Athens.

The country has long claimed they were illegally acquired during a period of foreign occupation, while British officials have rebuffed repeated demands for their return.

Sections of the Parthenon Marbles in London’s British Museum (Matthew Fearn/PA)

Christopher Marinello, a lawyer and expert in recovering stolen art, told the PA news agency that the theft exposes the museum to questions over the safety of the ancient sculptures.

He said: “It makes one wonder whether the Parthenon Marbles are safe in the British Museum after all, and perhaps they should be returned to the museum in Athens for their security.”

The head of the Association of Greek Archaeologists, Despina Koutsoumba, said her colleagues are “worried” about how many Greek items are missing.

She told the BBC: “We want to tell the British Museum that they cannot anymore say that Greek culture heritage is more protected in the British Museum.

“It is obvious that it is very well protected in Greece and not in the British Museum.”

Mr Loughton was also asked about emails leaked to BBC News that claim the British Museum was alerted to the thefts in 2021 and ignored the report.

He said: “With respect, all that’s come out is a few emails rather than the bigger picture.

“But the British Museum will need to account for that because if people are trying to report potential objects having appeared outside of the museum then absolutely those need to be investigated and potentially referred to the police.

“So what action was taken? What checks and balances are there at the museum?

“Also putting into context… the British Museum has the most online documentation online in the world. There are over two million objects available online to see.”

The Daily Telegraph has reported that the number of stolen items is believed to be “well over 1,000″ and “closer to 2,000”, with a value running into “millions of pounds”.

An independent review of security has been launched and the matter is also under investigation by the economic crime command of the Metropolitan Police.

No arrests have been made.

The review will be led by former museum trustee Sir Nigel Boardman and Lucy D’Orsi, Chief Constable of British Transport Police.