The director of the British Museum has stepped down amid an investigation into the alleged theft of gold and artifacts from the famous London institution.

Hartwig Fischer's resignation has been accepted by the museum's board of trustees.

Explaining his decision in a statement on Friday, Fischer said: "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.

"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 museum said in a statement last week that a number of items from the museum's collection were found to be "missing, stolen or damaged," leading to the dismissal of an employee and an investigation by the Metropolitan Police.

"The British Museum has launched an independent review of security after items from the collection were found to be missing, stolen or damaged. A member of staff has been dismissed, and the Museum will now be taking legal action against the individual," it said.

"The matter is also under investigation by the Economic Crime Command of the Metropolitan Police."

In a statement provided to CNN, the Metropolitan Police said: "We have been working alongside the British Museum. There is currently an ongoing investigation -- there is no arrest and enquiries continue."

The majority of the items were "small pieces kept in a storeroom" belonging to one of the museum's collections. "They include gold jewelry and gems of semi-precious stones and glass dating from the 15th century BC to the 19th century AD," the museum said, adding none of the items had recently been on public display, and were kept mostly for academic and research purposes.

Fischer described the incident as "highly unusual," while George Osborne, chair of the museum, said it was a "sad day for all who love our British Museum, but we're determined to right the wrongs and use the experience to build a stronger Museum."