Tens of thousands of Internet users have gone online to question reports in China's state-run media saying an anti-corruption official found dead with 11 stab marks to his body had taken his own life.

The body of Xie Yexin, who worked as an anti-corruption official in the central Chinese province of Hubei, was discovered in his office on Tuesday next to a knife wrapped in a paper napkin with a knife, press reports said.

By Friday, Xie's death was the third most talked-about subject on the popular news site Sina.com, while the same company's Weibo -- China's answer to Twitter -- had more than 130,000 comments on the subject.

The vast majority were sceptical about the suicide verdict, put forward by Chinese police despite an autopsy showing Xie had been stabbed 11 times and had his throat cut. Xie's family has also rejected the official version of events.

"In China, anything is possible. What a miraculous country!" one blogger, Qiuzuochang, posted on Sina's Weibo.

"Chinese people really are stupid," said another, posting under the name Xiyanglaohuangsheng.

"Ending your life with eight cuts puts us well behind Japan -- there, they only have to stab themselves once."

China has the world's largest online population, with 485 million Internet users, and last month the Internet giant Sina said its weibo, by far the country's biggest microblogging site, had surpassed 200 million users.

The growing influence of weibos, which are harder to control than the country's state-run media, appears to have worried Chinese authorities, who last week urge them to stop the spread of "false and harmful information".