COLORADO SPRINGS, Dec 31: World 100 and 200-metre champion Kelli White and five other American athletes have tested positive for the stimulant modafinil, the U.S. Olympic Committee (USOC) announced on Tuesday.

White, sprinter Chryste Gaines, hurdlers Sandra Glover, Chris Phillips and Eric Thomas, and hammer thrower John McEwen tested positive for the stimulant at either the U.S. or world athletics championships, the USOC said in a statement.

McEwen also tested positive for the designer steroid tetrahydrogestrinone (THG), the USOC said. The USOC also said cyclist Adham Sbeih tested positive for erythropoietin (EPO) at the U.S. Cycling Federation (USCF) Elite Track National Championships in August.

"USADA's (U.S. Anti-Doping Agency) Anti-Doping Review Board determined that sufficient evidence of doping exists to proceed further in seven cases," the USOC said.

"All seven athletes are disputing their cases in the USADA adjudication process," the USOC said. "If a sanction is imposed, USADA will make the announcement at a later date." -Reuters