Sun Yang, China's double Olympic swimming gold medallist and world record over 1500m freestyle, has been suspended from all commercial activities for breaching a "series of team rules", according to Xinhua.

The Zhejiang College of Sports, to which Sun is affiliated, has also withheld his monthly allowance after the 21-year-old, who won the 400m and 1500m at the London 2012 Olympic Games, skipped more than 40 days of training, the agency reported.

"Although Sun Yang has realised what was wrong with him and he promised to put it right, we have to punish him as everyone is equal when it comes to rules," college dean Li Jianshe was quoted as saying.

Sun, who became the first Chinese man to win an Olympic swimming title when he claimed the 400m crown in London, is also reported to have fallen out with his long-time coach in China Zhu Zhigen over commercial commitments.

Sun posted photos online of himself enjoying time out with flight attendant girlfriend Nian Nian. Zhu is reported to disapprove, the stress of his A-grade aquatic student asking for a new coach after a confrontation between the two men over the intensity of Sun's training and management regime, leading to this: 

"Having been Sun's coach for 10 years, Zhu Zhigen was very disappointed and suffered a relapse of high blood pressure and a thyroid nodule." - reported a Chinese newspaper.

However, Li is quoted as saying: "Zhu has been coaching Sun Yang for 10 years and I don't think their bond is so fragile."

Sun Yang was reported to have earned $18 million in endorsement funds after his Olympic success: the biggest deal ever in Chinese Olympic sport. Coca-Cola is said to have made up the bulk of the money, while the swimmer's contract with the Chinese Swimming Federation requires him to hand a third of his earnings to the rest of the Olympic swimming team. 

That meant that each member of the squad would get about $150,000 if the money is shared evenly. Sun then had to give the federation $6m of his earnings. Huge incentives anywhere, let alone in China.

According to Xinhua, Sun's training in Australia has cost the Chinese government $1.57 million. Some of that went to Denis Cotterrell, the Australian coach rumoured to have been paid a quarter of a million dollar bonus for Sun's success. "What the Chinese offered me for a month, I could live on for a year," Cotterell was reported to have said.