China has banned its 21-year-old women’s 100-metres champion for life after she tested positive for banned drugs at the National Games.

Wang Jing, from southeastern Fujian province, was the third athlete to fail a doping test at the games. Competition is intense at the quadrennial event since a strong performance can lead to a place on the national team.

The sprinter, who was on the China team at last year’s Beijing Olympics, won the 100 metres last week in a time of 11.50 seconds. That was more than a second outside the world record of 10.49 seconds. After the race, she tested positive for testosterone.

Ms Wang said that she accepted the results but insisted she was innocent. “I have never taken any drug willingly in my life and I have never accepted any drug from anybody,” she said.

Ms Wang appealed for further checks on her test results. “I strongly asked the concerned bodies to investigate the whole case and tell everybody why my sample tested positive,” she said.

Ms Wang had been among China’s bright young hopes to improve its international performance in track and field after she finished fourth in the 200 metres at the 2006 Junior World Championships.

Zhang Yongliang, director of competition at the Chinese Athletics Administration Centre, said: “The life ban is a very severe punishment for athletes. We hoped it would make those are willing to cheat think again.”

He said that the centre had taken tough anti-doping measures at the games but had still failed to stop some offenders. “Some athletes are still playing with fire.”

Previously, the shooter Li Jie tested positive for the beta-blocker propranolol that can help to steady the hand, and the rower Guo Linna tested positive for 19-norandrostenedione, a precursor for the anabolic steroid nandrolone. Ms Guo was banned from competition for four years and fined 15,000 yuan (£1,500). Her coach was banned for life because he had already been involved in two positive doping cases, the first dating back to 2001.

In past years, the National Games have produced a string of scandals, from doping to sabotage and on-court cheating.

China's national teams have taken a zero-tolerance stance on doping, but provincial teams are considered more susceptible because coaches are eager for the cash and promotions that come with strong performances by their athletes.

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game