LOS ANGELES: Jessica Hardy, an American who qualified to swim the 50-metre freestyle and 100 breaststroke at the Beijing Olympics, tested positive for a banned substance, Swimming World magazine reported.

The magazine’s website said an unidentified coach not on the Olympic staff confirmed the positive test while NBC television’s Olympic website reported that both “A” and “B” samples from Hardy have tested positive.

Both organisations cited unnamed athletes as saying Hardy is no longer at the US swim team’s training camp after the results, which NBC said came from a test taken at the US Olympic trials that concluded earlier this month.

Hardy won the 100 breast and was second in the 50 free at the trials in Omaha, Nebraska, but could face a two-year ban for a positive dope test. Expedited arbitration proceedings have already started to decide if Hardy will remain in the US lineup for Beijing, NBC reported, saying the banned substance in question is thought to be a stimulant.

Should Hardy not compete at Beijing, it would be a major blow to American medal hopes in the 100 breast, her premier event, and hurt US relay chances as well as bringing a cloud of doping controversy over the US swim squad in Beijing.

A strong breaststroke leg from Hardy would be important for a US 400 medley relay that is expected to face a fight for gold with Australia. Hardy, 21, set a world 100 breast record of 1min 06.20s at the 2005 World Championships in Montreal, a time that remains an American record.

Hardy was on the US Olympic roster submitted on Wednesday to the International Olympic Committee for the Beijing Games, meaning the places in her races would have to be filled by other swimmers already on the US team.