Updated

The Japanese owner of a Pierre-Auguste Renoir painting, which was stolen from his home in 2000, was surprised to discover that Sotheby’s in London sold it for more than $1,000,000 in February.

The oil painting, “Madame Valtat” -- completed and signed by the famous French Impressionist in 1903 -- was taken, along with five other works from a Tokyo man’s home, in August 2000, according to investigative sources cited in a Japan Times report.

The art collector -- who has not been identified -- informed Japanese police after noticing in March the piece had been sold at auction for $1.6 million.

Japanese investigators have not yet identified the thief, who also nabbed works by Russian-born French painter Marc Chagall and Japanese artist Ikuo Hirayama from the man's home.

The Renoir had not appeared on a list of lost or stolen artwork on an international database, so Sotheby’s did not catch it before it went on the block. The Japan Times reported that the owner notified police in Japan after the heist, but neither he nor the authorities contacted the stolen items database to have the works listed.

The painting’s owner intends to get the piece back, but may have trouble identifying who bought it because Sotheby’s keeps client information confidential.

Sotheby’s told Japan’s Kyodo News that the seller of the Renoir had acquired it legitimately in 2000 and was able to prove rightful ownership with representations and warranties on the painting.

Investigators believe the painting was probably sold to the seller shortly after it was stolen. Sotheby’s said it has been looking into the possibility the work was stolen and is communicating with the parties involved.

The Impressionist portrait is of Suzanne Valtat, the wife of Renoir’s close friend and painter Louis Valtat.

Click for more from the Japan Times.