China have been cleared of fielding underage gymnasts at the Beijing Olympics, but officials will continue to investigate claims that the country breached the rules at the 2000 Olympics in Sydney.

The International Federation of Gymnastics (FIG) said it was happy all of the Chinese female competitors were aged over 16 in the summer Games but said doubts remained over the eligibility of Dong Fangxiao and Yang Yun in Sydney.

"Originals of official documents received from the Chinese Gymnastics Association, specifically passports, identity cards and family booklets or 'Household Registers', confirm the ages of the athletes," FIG said in a statement. On the 2000 case, it said: "The FIG does not consider the explanations and evidence provided to date as satisfactory."

Dong showed officials in Beijing this summer documents that suggested she was only 14 in 2000, according to Andre Gueisbuhler, the secretary general of the FIG. Her blog indicates she was underage in Sydney, too.

Bronze medallist on the uneven bars in 2000, Dong also said in an interview on Chinese television broadcast last year that she was 14 in Sydney. However, Dong, a technical official in Beijing, denies the claims and was willing to assist the investigation.

“If the FIG wants to investigate this matter,” she said, “I will provide every form of documentation.” She claimed she made a mistake in the television interview. “Everyone has misspoken. On television shows, there are always slips of the tongue.”

FIG introduced the minimum age in 1997 to tackle concerns over the stress placed on young gymnasts' bodies at an elite level.