The IAAF has requested assistance from the Chinese Athletics Association with an investigation into a letter alleging state-backed doping in Chinese athletics.

Website Tencent on Wednesday reported that Chinese 3,000 and 10,000 metres world-record holder Wang Junxia admitted to being forced into doping almost 21 years ago.

A letter dating back to 1995 was said to have been written by Wang, who smashed the world records in 1993, and signed by nine of her team-mates claiming they were forced into taking "large doses of illegal drugs over the years".

World governing body the IAAF on Friday said they are looking into the authenticity of the letter.

An IAAF statement read: "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."

The IAAF said Wang, an Olympic champion and silver medallist in 1996, could be stripped of her world record's if they can prove the letter is genuine.

The statement continued: "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 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 record will not continue to be regarded as a world record by the IAAF."

Athletics' reputation has taking a battering in recent times after Russia was banned from competition by the IAAF following allegations made in a report by an independent commission set up by the World Anti-Doping Agency.

The second part of the report said the IAAF must have been aware of doping in the sport and claimed former IAAF president Lamine Diack "was responsible for organising and enabling the conspiracy and corruption".