Track and field's governing body pulled a surprise drug test on China's remarkable women distance runners, including Wang Junxia, who set the world record for the 10,000 meters and 3,000 meters in September.
No results have been made public of the tests which took place last week.A group from the International Amateur Athletic Federation group flew to northern Liaoning province to test the women, according to the official Xinhua News Agency said.
At the same time, Xinhua reported that 24 athletes, including a former women's weightlifting world record holder, tested positive for use of performance-enhancing drugs this year.
None of the Chinese women distance runners who repeatedly shattered world records were on the list issued by the Chinese Olympic Anti-drug Committee.
Their performances during the year led to suspicion they used performance-enhancing drugs, a claim heatedly denied by the runners and their coach.
Among those testing positive during the year were Xing Fen, the weightlifter who won a gold medal at the 1990 Asian Games, and shotputter Zhou Tianhua, Xinhua said.
"As soon as we discovered our athletes taking illegal performance-enhancing drugs, we would punish them strictly," Yang Tianle, spokesman for the anti-drug committee, was quoted as saying.
It did not give details on the punishments received by the athletes who tested positive.