North Korea was barred from the 1993 world championships after FIG officials discovered Kim Gwang Suk, the 1991 gold medalist on uneven bars, was listed as 15 for three years in a row. Romania admitted in 2002 that several gymnasts' ages had been falsified, including Olympic medalists Gina Gogean and Alexandra Marinescu.

"We applaud the serious efforts of the International Gymnastics Federation and International Olympic Committee to conduct an investigation given the level of speculation that existed," said Steve Penny, president of USA Gymnastics. "We believe the continuing investigation regarding the evidence from the Olympic Games in Sydney underscores the importance of maintaining a fair field of play and identifying methods to prevent questions of this nature in the future."

While it continues to investigate the ages of Dong and Yang, the FIG also is exploring its legal options and what sanctions might be available. The FIG's statute of limitations in disciplinary matters is five years, and 10 years for criminal cases, and the international federation is trying to determine whether Australia or Switzerland would have jurisdiction. If cause is found, the punishment could be as severe as stripping the medals.

"In our statutes, our code of discipline, we have a range of sanctions. It can be from a suspension, it can be taking medals away, it can be taking the rankings away," Gueisbuhler said. "Are we entitled to take action for medals or rankings at the Olympic Games? Or does this fall strictly under the IOC authority? We are looking at this moment at these questions."

But the medals aren't really the issue, said Dominique Dawes, a member of the U.S. team that finished fourth in Sydney.

"The important issue is them righting a wrong and hopefully prohibiting future Olympians from being underage," Dawes said. "It's really about making sure every athlete is doing things the right way."

Gueisbuhler said the documents Dong used for her Beijing credential list her birthdate as Jan. 23, 1986, which would have made her 14 — and too young — for the Sydney Games. Dong was a national technical official in Beijing, working as the secretary on vault. She was not part of any judging panel.

"If that document is the correct one, that would suggest she was 14 years old at the Sydney Olympic Games," Gueisbuhler said.

Dong's birthdate in the FIG database is listed as Jan. 20, 1983.

Dong's blog also says she was born in the Year of the Ox in the Chinese zodiac, which dated from Feb. 20, 1985, to Feb. 8, 1986. Dong has not denied that, but she refused to answer any questions about her age, telling the AP last week, "I've left the gymnastics team."

"If the FIG wants to investigate this matter," she added, "I will provide every form of documentation."

The FIG also has a copy of Yang's 2007 interview, in which she seems to contradict her official birthdate. Yang's birthdate is listed as Dec. 2, 1984.