An International Gymnastics Federation (FIG) probe has found Dong was younger than the minimum age requirement of 16 during the 2000 Games in Sydney after she registered different ages at Sydney and the Beijing Games eight years later.

A statement from FIG said: "Consequently, the results obtained by Dong Fangxiao at the 2000 Sydney Olympic Games have been cancelled.

"The FIG Executive Committee decision was forwarded to the IOC (International Olympic Committee) Executive Board with the recommendation to withdraw the bronze medal obtained by the Chinese team including the results of Dong Fangxiao in Sydney."

Dong's official birthdate is listed as January 20, 1983.

But the FIG said accreditation information for the Beijing Olympics, where Dong worked as a national technical official, listed her birthdate as January 1986.

That would have made Dong 14 in Sydney.

Dong's blog also said she was born in the Year of the Ox in the Chinese zodiac, which dated from February 20, 1985, to February 8, 1986.

Bruno Grandi, the President of FIG, said: "Young gymnasts cannot be manipulated.

"Athletes must be protected.

"To prevent such fraud in the future, a new licensing system has been implemented by the FIG."

Chinese teammate Yang Yun, a bronze medallist in the team event as well as the uneven bars and who was also under investigation, was cleared of breaking the rules but issued with a warning.

Dong will also have her results at the 1999 artistic gymnastics World Championships in Tianjin cancelled, along with those obtained at the FIG World Cup Series from 1999 to 2000 and at the 2000 artistic gymnastics World Cup final in Glasgow, the statement said.

The IOC has said previously it would take "necessary measures" if any gymnasts were found to be underage.

Mark Adams, the spokesman for the IOC, said: "We can confirm that we have received the ruling from the FIG in the case concerning Dong Fangxiao and Yang Yun, and we take due note of their decision.

"Clearly, we need to take time to consider the findings before the Executive Board can consider the matter."

The United States was fourth at the Sydney Games.

Dominque Dawes, a member of the US team, said: "I'm happy to know that justice is being served."

Zhang Haifeng, the Chinese Olympic Committee's (COC) spokesman at the Vancouver Olympics, called the decision an "old story."

He said: "That was in 2000.

"Now is 2010.

"This was 10 years ago."