A ring and a diamond necklace worth $1.2 million were stolen at the world's leading antiques fair in The Netherlands, a spokesman said.
"A ring with a big sapphire and a diamond necklace belonging to London jeweller Hancock were stolen," fair spokesman Titia Vellenga said.
The Tefaf fair in the Dutch city of Maastricht opened on March 12 and closed on Sunday.
The 11.65-carat ring and the 7.23-carat necklace disappeared between 5 p.m. and 6 p.m. (1600 and 1700 GMT) and police were investigating, Ms Vellenga said. Maastricht police officials could be reached for comment late Sunday.
The 23rd edition of the Tefaf fair drew a crowd of 73,000 visitors this year.
More than 260 art and antiques dealers showed 30,000 paintings, sculptures, pieces of furniture, jewellery, china, clothes and manuscripts.
The fair's biggest sale was a 1534 painting by German artist Lukas Cranach, David and Bathsheba, which went for €5.3 million, said Ms Vellenga.