Photo provided to China Daily

Ma fulfilled his promise. His first ink painting of a cloudlike object was auctioned for 2.42 million yuan on Taobao.com on Dec 22. He gave all the money to charity.

A year later, he wrote a piece of calligraphy of two Chinese characters. It was sold at a charity ball for 4.68 million yuan to an entrepreneur from Zhejiang province.

The man who bought Ma's blue-and-white Paradise is Qian Fenglei, a 39-year-old businessman.

On the list of Forbes' philanthropists for 2014, Qian was No 74. He bought a jade Buddha at 20 million yuan in 2012 and an oil painting by Zeng Fanzhi at HK$30 million ($3.87 million) in 2013, both at an annual charity dinner organized by Smile Angel Foundation that helps children with cleft lips.

Zeng Fanzhi's work The Last Supper was sold for $23 million in 2013, setting the auction record for the most expensive piece of modern Asian art.

It's also not the first time he co-created with people from other fields for the purpose of charity. In 2012, he worked with movie director Feng Xiaogang to complete an oil painting together. It sold at Bazaar's charity dinner for 17 million yuan.

Some artists and art critics says on social networks that the high price auctioned for billionaire Ma and artist Zeng's work humiliates China's art world. Ma's works is blamed to be "not as good as" many established artists but they're sold better than well-known artists in auction houses just because of his influence in business.

"Ma got lots of criticism for his works. But for an auction aimed for charity, I don't think the price should be associated with its art value," says Dong Guoqiang, president of the Beijing Council International Auction Company.

Dong says it's difficult to hold a charity auction. Before blaming Ma's artworks, people should think of what they have done for charity, he adds.

Ma is not the first celebrity to paint for charities. Film star Zhao Wei, TV host Ni Ping and movie mogul Wang Zhongjun are among those who have painted for charity.