File photo of China’s Ye Shiwen posing with her gold medal on the podium during the women’s 400m individual medley victory ceremony at the London 2012 Olympic Games

Ye Shiwen won gold after a stunning world-record time in the 400 IM Saturday (David Gray -- Reuters)

Ye Shiwen won gold after a stunning world-record time in the 400 IM Saturday (David Gray — Reuters)

China’s Ye Shiwen poses with her gold medal on the podium during the women’s 400m individual medley victory ceremony at the London 2012 Olympic Games at the Aquatics Centre in this July 28, 2012 file photograph. Ye said on Monday that her “results come from hard work and training” and that she “would never use any banned drugs”. All medal winners at the Olympics are drug tested, according to media reports. REUTERS/David Gray (BRITAIN – Tags: SPORT OLYMPICS SWIMMING)