An 18th-century Chinese vase forgotten for decades in a shoe box in a French attic sold for 16.2 million euros (US$19 million) at Sotheby's in Paris on Tuesday -- more than 30 times the estimate.

Experts at the auction house said the exquisite porcelain vessel was made for the Qing dynasty Emperor Qianlong and had set a guide price of a much more modest 500,000 euros.

"This is a major work of art, it is as if we had just discovered a Caravaggio," Olivier Valmier, the Asian arts expert at the auction house, told reporters before the sale.

The vase, which was in perfect condition, "is the only known example in the world bearing such detail," he added.

Rare porcelain from the Qianlong period has been going for astronomical prices recently, with a bowl sold last April by Sotheby's in Hong Kong for 30.4 million dollars.

The vase -- which is decorated with idealised images of deer and cranes -- was found by chance among dozens of other pieces of Chinoiserie in the attic of a house in France earlier this year.

The family -- from near Paris -- had acquired it at the end of the 19th century but it has lain unloved in a shoe box in the attic for decades.

"We didn't like the vase too much, and my grandparents didn't like it either," said the owner of the piece, who only got in touch with Sotheby's in March.

It was still in the shoe box when it was presented to Sotheby's experts for authentification.

The staggering price paid by a young Chinese collector, who was at the auction himself, is the highest ever recorded by the auction house in Paris.

The man, who was wearing a jogging top, beat off bids from other Chinese collectors, mostly over the phone.

The collector, who has has not been named, also did the bidding himself -- a rarity at this level of auction.

The polychrome vase with its idyllic landscape of mist-topped mountains and pine trees also carries a six-character "reign mark" on its base.

The only other similar vase that has so far come to light is in the Guimet museum of Asiatic arts in Paris, though it does not have the cranes.

Only four like pieces have been documented as coming from the imperial workshops in the 1790s.

"Such elaborate and challenging designs are exceedingly rare on Qing imperial porcelain," Sotheby's said on its website.