Items of rare medieval Chinese jewellery have been stolen from the British Museum in London.
These S-shaped earring were among the stolen items
The 15 pieces were stolen by a thief believed to be masquerading as a visitor to the museum on Friday.
"We believe the theft took place while the gallery was open to the public as no alarms were activated and there was no sign of a break-in," said police.
The theft of the "historically important" items was not discovered by staff until Saturday morning.
Police will investigate the possibility that the Chinese jewels, including ornate hairpins and fingernail guards, were stolen to order for a private collector.
Despite a sophisticated security system and guards patrolling the museum, there have been two major thefts from the British Museum since 1990.
In 1990, a 17th-Century Japanese statuette worth £100,000 vanished from the museum in central London, home to the Rosetta Stone and the Elgin Marbles.
In 1993, burglars broke in through the roof and stole £250,000 worth of Roman coins and jewellery.