A painting that sold for over $11 million under the name of a renowned Chinese artist was actually made decades after his death by a student in a classroom exercise, a group of artists has alleged.
The nude, entitled "The Body of Miss Jiang Biwei", was accredited to the well-known artist Xu Beihong and sold at auction in June 2010 for 72.8 million yuan ($11.4 million).
But an open letter posted on several online forums by a group of graduates from the Central Academy of Fine Arts in Beijing said the oil painting was actually produced by one of them in 1983 -- 30 years after Xu's death.
"Recently, after contacting each other, we have doubted a piece of news we read on the Internet," says the letter.
"This is a picture that cannot be more familiar to our class. It's a classroom exercise done by one of us. We cannot determine which of us produced it, but many of us have kept paintings from the class."
Several oil paintings drawn from different angles and depicting a nude woman who looks strikingly similar to that in the art work were posted online along with the letter.
The artists say the model, who they identify only by the letter L, was a young girl who had travelled to the capital from rural China looking for work.
"L's hairstyle is common to the 1980s, her figure is also very unique... and left a deep impression on students," the letter states.
"For Mr. Xu Beihong's painting to share exactly the same lining colour, model standing posture, body features, hairstyle, and facial features as our paintings, this is impossible."
The auction house which sold the painting, Beijing Jiuge International Auction Company, said it had no immediate comment to make on the letter.
Xu is best known for his ink paintings of horses, although he is also widely regarded as a pioneer of oil painting in China.
One of his ink works, entitled "Galloping Horse," sold for 17 million yuan at a local auction in November last year.
China recently overtook the United States as the biggest auction market for art and collectable objects after sales more than doubled in a single year, according to research for the French Auction Market Authority.