Two members of that squad -- Dong Fangxiao and Yang Yun -- remain under scrutiny.
The International Gymnastics Federation said in a statement that it "does not consider the explanations and evidence provided to date in regards to these athletes as satisfactory."
Dong got a Beijing Olympics credential with documents that suggest she was only 14 in 2000, said Andre Gueisbuhler, secretary general of the FIG. Her blog also indicates she was underage in Sydney, when China won the bronze medal in the team competition.
Yang, who also won a bronze medal on the uneven bars in 2000, said in a June 2007 interview that aired on state broadcaster China Central Television that she was 14 in Sydney. Gymnasts must turn 16 during the Olympic year to compete.
"I would hope that the whole world in sport realizes that the FIG is serious about these rules and the ethics and moral questions," Gueisbuhler said.
Calls to Yang and Dong's mobile phones rang unanswered Wednesday.
"We are satisfied with the information provided by FIG, and we now consider the (2008) matter closed," said Emmanuelle Moreau, spokeswoman for the International Olympic Committee.
"Clearly they feel that there is more to be looked at for Sydney," Moreau added. "We encourage them to pursue their inquiry and shed some light on these cases. We now rely on them to get to the bottom of that and get back to us."
Doubts about the ages of China's current gymnasts swirled for months before the Beijing Olympics, with media reports and online records suggesting some girls could be as young as 14. Three days before the games ended, the IOC asked the FIG to look into the matter one last time.
The investigation was expanded after questions were raised about the 2000 team.
Underage gymnasts have been a problem since the 1980s, when the minimum age was raised from 14 to 15. The minimum age was raised to its current 16 in 1997.