SAINT-DENIS, France -- The IOC asked U.S. Olympic officials and track's world governing body Thursday to investigate allegations that American runner Jerome Young was allowed to compete in the Sydney Olympics despite a positive drug test.

IOC president Jacques Rogge sent a letter to the U.S. Olympic Committee and the International Association of Athletics Federations "strongly urging them to pursue the matter."

Rogge also asked the World Anti-Doping Agency to assist the inquiry "by using all means and powers at its disposal."

The IAAF's rule-making council said it could only reopen the case if the athlete comes forward and admits to the positive test.

The USOC issued a statement saying the matter already had been reviewed by the international court of arbitration for sport and by the McLaren Commission, an independent group formed in 2000 to examine USA Track & Field's drug testing policies.

"We consider this case to have already been adjudicated in accordance with the applicable rules of the time," the USOC said. "Any attempt to reexamine this case using today's rules -- rather than the rules that were in place at the time -- is impractical and does nothing to further the international anti-doping effort."

The International Olympic Committee's intervention came a day after a report in the Los Angeles Times that Young tested positive for steroids in 1999 but was cleared to run in the 2000 Olympics. Young won a gold medal as part of the U.S. 1,600-meter relay team.

On Tuesday, Young won the 400 meters at the World Championships here for his first individual title. He is set to run in the 1,600-meter relay this weekend.

It had been known that an American athlete tested positive before the Sydney Olympics, was exonerated by U.S. officials and won a gold medal. U.S. Olympic and track and field officials refused to disclose the name.

"All along in this affair, the IOC has constantly pushed for the unnamed athlete's identity to be disclosed, together with all the details of the case," the IOC said.

If the allegations against Young are true," they would lift the suspicion that hangs over innocent athletes," the IOC added.

Dick Pound, president of the anti-doping agency, said Wednesday that the legitimacy of the U.S. victory was "shattered" by the report and called for the team's medals to be stripped.

The IAAF, which had demanded that USA Track & Field release the name of the athlete, said it must respect an arbitration ruling protecting the identity of the athlete.

But "the case itself is not closed," IAAF vice president and anti-doping chief Arne Ljungqvist added. "If the athlete comes voluntarily forward, then a new situation comes up and we have a basis for action."

"I think sooner or later this case will become an open book," he said. "There will be such pressure on so many organizations.''

The Times reported that Young tested positive for the performance-enhancing steroid nandrolone on June 26, 1999. He tested negative for banned substances two weeks before and six days after that test, the newspaper reported.

Steroid violations normally carry a two-year suspension.

The Times said Young was suspended in April 2000 but the penalty was overturned in July 2000 by an appeals board; no reason was given. Less than a week later, Young finished fourth at the U.S. trials for the Sydney Olympics, earning a slot on the relay team.

Young ran the first leg in the opening round and semifinal heats but didn't run in the final. The U.S. team, anchored by Michael Johnson, finished ahead of the Jamaicans and Russians.