Xu Boyang holds the painting that he declared was painted by his father.Photos: Southern Weekly

An oil painting by a famous Chinese artist that sold at auction for millions of yuan may in fact be a fake after a group of graduates from the Central Academy of Fine Arts (CAFA) said the work was inked by a classmate of theirs in 1983.

The masterpiece, auctioned by Beijing Jiuge International Auction Company in June last year for 72.8 million yuan ($11.25 million), was thought to have been painted by Chinese artist Xu Beihong (1895-1953) who made his fame from shuimohua or Chinese ink paintings and was regarded as a pioneer of oil paintings depicting with Chinese themes.

The disputed painting represents a naked woman believed to be Xu's wife, Jiang Biwei, in the 1920s.

The authenticity of the picture had been confirmed by Xu's eldest son, Xu Boyang, through a written endorsement in September 2007.

However, 10 CAFA graduates declared Thursday that the work was actually painted by one of their classmates in May 1983, as an assignment, according to Southern Weekly. They added the model was a girl from Jiangsu Province.

Claiming that nearly 20 students had attended that class, the graduates attached five of their works drawn for the same assignment to an open letter. According to the report, the paintings resembled the auctioned piece.

Yang Songlin, head of Shandong Province's Oil Painting Association and one of the co-authors of the open letter, told China National Radio (CNR) that although he could not recall who the real painter was, he was confident it had been made by a classmate.

"I can't say that Xu never drew a woman like this, but it is absolutely impossible to have a painting with such a close similarity, and I have never seen any of Xu's works like this before," Yang said.

The Beijing Jiuge International Auction Company made no comments yesterday when the Global Times reached it.

Meanwhile, Chinese artists cast doubts over the painting.

Renowned artist Chen Danqing was quoted as saying by CNR that the picture cannot be called a counterfeit since it is not even a copy of one of Xu's paintings.

"It is not fake at all since a counterfeit would manage to imitate Xu's work. This one is a totally different picture that has nothing to do with Xu and was deliberately misrepresented as his painting," Chen said, adding that the disparities are quite obvious.

"I am surprised that they cannot distinguish the difference between a work from the 1920s and the 1980s as well as differences between the appearance of southern and northern girls," Chen said.

Lü Lixin, a scholar studying Xu's paintings at Tsinghua University's Academy of Arts & Design, said that photos of Jiang Biwei showed she was not the woman depicted in the painting.

As of press time on Friday, there was no reported response from the buyer of the painting and no assessment of the painting was reported.

Zhao Li, director of Chinese Modern & Contemporary Art Document Research Center, told the Global Times that mistakes can be made when identifying and evaluating art works, but that the crucial problem was the lack of an official authority to certify the authenticity of any artwork.

"There is no strict and standardized assessment mechanism for art appraisal in China. Once a work is discovered to be fake, there is no regulation to stipulate which party should shoulder the responsibility and face punishment," Zhao said.

According to the country's Auction Law, auctioneers are not allowed to promise the authenticity or the quality of the products, which is believed to exempt auction companies from taking the blame.

But according to rules in the Chinese auction industry, the auction company is obliged to refund products if at least three experts identify the work as a counterfeit, Zhao said, adding that there is no set compensation amount stipulated.

Zhao said with Chinese art taking pole position in many auctions around the world and with rising prices, such events as fake fine art sales have been grabbing more and more attention.

In 2010, China accounted for 33 percent of global fine art sales, followed by the US, the UK and France, according to a report by Artprice.com, a leading French art appraisal website.

"A good fine art auction would amount to tens of millions of yuan now. Prices are soaring so dramatically that a mistake will mean huge costs for a buyer. It is more urgent now than ever to regulate the industry so as to reduce losses," Zhao said.