Johnson (centre) and his US team-mates celebrate Olympic gold in Sydney
Athletics legend Michael Johnson could lose his Olympic 400m relay gold from 2000 as a result of the Jerome Young doping case.
The International Olympic Committee (IOC) has launched disciplinary procedures to strip the US 4x400m team of their golds after US officials confirmed last week that Young failed a drugs test in 1999.
Young, who won 400m gold at this summer's World Championships, tested positive for banned steroid nandrolone before the Sydney Olympics but was allowed to compete by USA Track and Field.
He subsequently ran in the heats of the relay in Sydney and was awarded one of the six gold medals given to the team.
If the US team are disqualified by the IOC, Johnson and his team-mates would have to hand back their gold medals. Silver medallists Nigeria would be promoted to gold.
The International Association of Athletics Federations (IAAF) has said it cannot take any action, having been told at the Court of Arbitration for Sport in Lausanne that US officials did not have to reveal the names of 13 of its athletes in disputed drugs cases.
Young's case only came to light after the Los Angeles Times published the news in the aftermath of Young's individual world gold medal in Paris.