In a scandal that has taken more than two decades to emerge, a Chinese journalist has claimed 10 of the country’s Olympic champions and world record holders have said they were part of a state-sponsored doping program.

Zhao Yu says double world record-holder Wang Junxia, along with nine other top runners, wrote him a letter in 1995 that said coach Ma Junren had forced them to take “large doses of illegal drugs over the years.”

The letter was posted online this week by Tencent Sports and reported by China Central Television (CCTV) and throughout Chinese state media.

Zhao says he attempted to include the doping allegations in his 1997 book about the coach and his athletes, “Revealing the Secrets of Ma’s Army,” but they were deleted and not made public until a new edition was published last year.

The journalist told CNN that “there is not only one letter, but also other letters and athletes’ diaries in the book” to support the claims.

The letter alleged that Ma would encourage Wang and her teammates to take pills and, if they refused, would personally inject them with drugs.

“We are humans, not animals,” it said.

Wang Junxia and controversial athletics coach Ma Junren in 2005.

In a statement, the International Association of Athletics Federations (IAAF) said it was investigating the claims and attempting to verify the letter.

“The CCTV story confirms that the existence of the letter allegedly written to the journalist only became known yesterday,” the statement said.

“Therefore the IAAF’s first action must be to verify that the letter is genuine. In this respect, the IAAF has asked the Chinese Athletics Association to assist it in that process. In any case, IAAF Competition Rule 263.3 (e) note (ii) clearly states that, if anyone makes an admission of guilt, the IAAF can take action.

“If an athlete has admitted that, at some time prior to achieving a world record, he or she had used or taken advantage of a substance or technique prohibited at that time, then, subject to the advice of the Medical and Anti-Doping Commission, such a record will not continue to be regarded as a world record by the IAAF.”

Neither Wang nor the Chinese Athletics Association immediately responded to a CNN request for comment.

Ma has made no public comments on the allegations.

The athlete first came to global prominence when she led a team coached by Ma to success in the 1993 World Championships in Athletics in Stuttgart.

She won the world 10,000 meters gold before setting a world 10,000 meters record of 29:31.78 at the Chinese national games in Beijing a few weeks afterwards – a time no other runner has come within 20 seconds of – and also holds the 3,000 meters record.

Wang, who in previous years has denied being part of a doping program, was inducted into the IAAF Hall of Fame in 2012.

Ma and his athletes were dubbed “Ma’s Family Army” by the press, but in 1995 Wang led a walkout amid discord and in 2000 the Chinese authorities fired him from their Olympics team after six athletes failed drug tests.

During his coaching career, he consistently put the success of his runners down to a rigorous training regime and the use of tonics including turtle's blood, the South China Morning Post reported. (CNN)

•Photo shows China’s Olympic runner Wang Junxia said to be among those who confessed to the state-sponsored doping programme.

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