A 1,000-year-old carved rock crystal ewer, one of only seven known surviving examples, has fetched 3.2 million pounds ($5.6 million) at a London auction, Christie's said.

The ewer is the same one that came up for auction in Britain in January this year, when it was catalogued as a 19th century French claret jug and valued at 100-200 pounds.

In fact experts now believe it is an extremely rare ewer from the Fatimid dynasty which ruled parts of northern Africa and the Middle East in the 10th-12th centuries.

Reflecting its importance it sold in January for 220,000 pounds, although auction house sources said that transaction was later 'annulled by agreement'. They gave no further details.

Christie's said the ewer, which sold to an anonymous client in the saleroom, was made for the court of the Fatimid rulers of Cairo in the late 10th or early 11th century. It was embellished in enamelled gold mounts made in 1854 by a French silversmith.

By the middle of the 11th century the Fatimid state had become so impoverished that much of the contents of the Royal Treasury had to be sold, including ewers, the auctioneer added.

The ewer was carved by hand from a single piece of rock crystal, and is decorated with cheetahs and link-chains.

Out of the other six surviving examples, one is in London's Victoria & Albert Museum, two are in the treasury of the Basilica of San Marco, Venice, one is in the Cathedral of Fermo, Italy, another is in the Louvre in Paris and one was stolen from the Museum of Limoges, France, in 1980.

There was one other known ewer, but it was dropped by an employee of a museum in Florence in 1998 and shattered irreparably, according to reports.

In April, rival auction house Sotheby's sold a 12 century key to the Kaaba in Makkah, for 9.2 million pounds, setting a new record for an Islamic work of art at auction.-Reuters