A major international diamond exhibition at the Natural History Museum was shut down three months early today after a Flying Squad tip-off that the priceless jewels could be stolen by an armed gang.
The display, which has attracted more than 70,000 visitors since it opened in July, was closed with immediate effect.
Included in the exhibition was the De Beers Millennium Star, a 203-carat pear-shaped diamond which was a target for thieves in a foiled robbery attempt on the Millennium Dome five years ago.
In that heist, on November 7, 2000, police were lying in wait for the gang as it tried to smash its way into the Dome with a mechanical digger for a haul valued at £350 million. This time around, fearing a more violent denouement, police took no chances and asked the museum last night to close its doors.
The Millennium Star is considered arguably the most perfect large diamond in the world and its appearance at the museum in South Kensington was the first time it had been seen in public since the foiled raid.
Dr Michael Dixon, director of the Natural History Museum, said: "Since we began planning this exhibition, we have followed police advice to the letter in terms of ensuring the security of our staff, our visitors, and the exhibition specimens.
"That advice changed on the afternoon of Tuesday November 22. It indicated a heightened criminal risk to the exhibition. The museums priority is the safety and security of our visitors and staff.
"Based on police advice, the only responsible course of action in this situation was to close the exhibition."
Other gems included in the popular exhibition are the Steinmetz Pink, the worlds largest pink flawless diamond; the Ocean Dream, the worlds largest naturally occurring deep blue-green diamond; and the Incomparable, which at 407.48 carats is the third largest cut diamond in existence.
Also on display was Scott Henshalls Spiderman dress, made almost entirely of diamonds, which was worn by singer Samantha Mumba at the premiere of Spiderman II. The tiara worn by Catherine Zeta Jones on her wedding day was another popular attraction.
A Scotland Yard spokeswoman said: "Officers from the Metropolitan Police Specialist Crime Directorate have been in consultation with the management of the Natural History Museum regarding the ongoing exhibition they have there.
"We have received information that leads us to believe that criminals were planning to target the exhibition. For the safety of staff, visitors and the exhibition specimens, we have advised the management to close the exhibition with immediate effect.
"We thank them for their co-operation in this matter."
The rest of the National History Museum will stay open as usual and all those with pre-booked tickets for the diamond display will receive a full refund.