Cartier diamond ring worth 750,000 lost by British Museum

Jewellery went missing in 2011 and prompts calls for increased security at central London museum

The British Museum has revealed that it lost a 750,000 diamond ring in 2011, raising concerns about the museums security procedures.

The Cartier ring went missing from the central London museum, but the circumstances behind its disappearance six years ago are unclear. The police were called but they decided not to take the matter further.

Another search took place in 2016 as, under its regulations, the museum had to report the ring as lost five years after its disappearance was first noted.

The ring was given to the museum by an anonymous donor and was kept in the study collection, an area not accessible to the public.

Experts said that if the item had been misplaced it reflected poor management and if it had been stolen the public should have been informed. Warning of the risk of theft by staff, one called for stricter security checks.

Chris Marinello, the founder of Art Recovery International, said that, given the British Museum is one of the UKs best-funded museums, it was pathetic the item went missing and even more so that it hasnt been more widely reported until now.

He said: Its a public museum and the publics property they should have disseminated this information. They should have sent out a theft alert to jewellery groups … as well as other buyers of these materials. This is not an inexpensive ring.

Marinello added: If its been misplaced that reflects badly on a museum as well funded as the British Museum. They owe it to the public to maintain these objects and provide sufficient security for them.

Roy Clare, former director of the Auckland War Memorial Museum in New Zealand, said that he was surprised that the loss was not immediately publicised. There may be good reasons for the delay, but I cant imagine what they might be, he said. Personally, Id have opted for immediate transparency on such a matter and recommended as much to trustees.

However James Ratcliffe, director of recoveries and general counsel at The Art Loss Register, said items can be misplaced on a regular basis, adding: Its hard to suggest fault when [the museum has a] collection of millions of items. I cannot say it indicates the museum is not doing their job properly.

Donna Yates, a lecturer in antiquities trafficking and art crime at the University of Glasgow, said: I dont think this says anything about the museums security, and I think British Museum security is commendable. This sounds like the sort of loss any organisation that deals with small and valuable objects faces. Maybe it was stolen. Maybe someones sleeve brushed against it and it tumbled into a heating grate. Maybe it was accidentally filed away in the wrong box and theres hope that itll be found again. Even when an organisation has perfect security, losses occur.

But Ton Cremers, the founder of the Museum Security Network and the former head of security at Amsterdams Rijksmuseum, said his initial reaction was that it had been a theft and an inside job.

He said some museums protect against inside thefts by imposing security checks on staff. He called on the British Museum to consider such a move, saying staff should not be allowed to use the visitor entrance.

Cremers said if the ring had been misplaced or lost then that reflected bad management. You can misplace a book but not a valuable item like this, he said.

Experts said that if the ring had been stolen it would be nearly impossible to find it and that only a small percentage of stolen jewellery is recovered.

A spokesperson for the British Museum said that thorough searches had been undertaken when the ring went missing and subsequently, adding: The museum takes the security of the collection extremely seriously. The museum has since reviewed its security and collections management procedures and dedicated significant investment to improved security across the estate.