U.S. sprinter Jerome Young upset the competition Tuesday to win a 400-meter gold medal at the World Championships in Paris. But he’s soon likely to find himself at the center of an international dispute over another gold medal. Young took home a gold in the 4x400-meter relay at the 2000 Sydney Olympic Games, one year after testing positive for a banned steroid, according to Olympic and track and field officials familiar with his case and documents obtained by the Los Angeles Times. While the positive drug test was well known at the time, his identity until now has been a closely guarded secret, leading to a long-running international furore in which track and field officials accused the US of covering up for athletes who test positive for drugs. Young, who has won gold medals in the 4x400 relay at the World Championships in 1997 and 2001, is believed to have tested positive for nandrolone, a banned substance, at a meet in Eugene, Oregon, on June 26, 1999. After the positive test, following USA Track & Field regulations, a three-member ‘‘doping hearing board’’ was convened in March 2000. It found there had been a violation and, according to documents obtained by The Times, the USATF suspended an athlete — whose name was blacked out on the document — in April 2000. Sources involved in the drug test case and subsequent appeal have confirmed for The Times that it was Young. After the suspension, Young asked for a hearing and a three-member ‘‘doping appeals board’’ was convened. On July 10, the board overturned the finding of a violation and made its ruling official the next day, five days before Young ran and finished fourth at the US trials for the Sydney Games — qualifying for the 4x400 relay team. He was one of six Americans awarded gold medals for that team’s victory in Sydney. However, Young’s identification as having tested positive will raise questions about whether the US legitimately earned its relay medals, said Dick Pound, the head of the World Anti-Doping Agency. ‘‘It does far more than cast doubt on the legitimacy’’ of the medals, Pound said. ‘‘It totally destroys it.’’ Pound and other Olympic and international track and field officials complain they have long been kept in the dark about the drug test and subsequent overturning of it. On Tuesday, Jacques Rogge, president of the International Olympic Committee, said that knowing about Young now would help all the athletes who were innocent — but nonetheless tainted by reports of a positive drug test. ‘‘As far as we were concerned,’’ Rogge said, ‘‘there was suspicion for all the other American athletes. We knew clearly that there was one American positive.’’ One of Young’s lawyers, Anita Raman of New York, declined to comment and another, Julie North, could not be reached. Craig Masback, USATF chief executive, referred questions to spokeswoman Jill Geer, who said, ‘‘We don’t comment on the identity of any athlete in an anti-doping case.’’ (LA Times-Washington Post)