The World Anti-Doping Agency and swimming's governing body appealed to sports' highest court to restore Jessica Hardy's two-year doping ban.
The Court of Arbitration for Sport said Friday that WADA and FINA want the American swimmer barred for two years and ruled out of the 2012 London Games. CAS is expected to rule within four months.
Hardy tested positive for the anabolic agent clenbuterol at the U.S. Olympic trials last July and missed the Beijing Games.
The American Arbitration Association reduced her ban to one year instead of the standard two this month. The arbitrators found the failed drug test was caused by a contaminated nutritional supplement and requested that Hardy not lose her eligibility for London.
International Olympic Committee rules state that athletes are barred from the next games if they incur a doping ban of at least six months. Hardy's suspension is to end July 31.
She was supposed to swim in Beijing in the 100-meter breaststroke, 50 freestyle and the 400 free relay.