Olympic gold medalist Tyler Hamilton has tested positive for a banned substance and is retiring from cycling.
Hamilton says Friday that his positive test stemmed from use of an over-the-counter antidepressant.
Hamilton told The Associated Press "there's nothing to fight about." He says he took a banned substance and accepts the consequences.
Tyler won gold at the Athens Games, but that success was overshadowed by a blood doping scandal. He served a two-year doping suspension that ended in 2007.
The new positive test - which the U.S. Anti-Doping Agency hasn't revealed - could bring a ban of eight years or more, essentially ending the career of the 38-year-old racer.