London: Olympic and world 400 metres champion LaShawn Merritt has failed three doping tests for a banned substance and accepted a provisional suspension, his lawyer said.
"LaShawn Merritt has accepted a provisional suspension as a result of positive drug tests caused by his use of an over-the-counter male enhancement product," the American athlete`s attorney Howard Jacobs said in a statement.
"His voluntary acceptance of a provisional suspension means that he has chosen not to compete until the case has been decided," the statement added.
The US Anti-Doping Agency (USADA) confirmed the positives contained prohormones of the banned male sex hormone testosterone and said in an email to Reuters its investigation of Merritt`s case was continuing. It will have no further comment until the legal process was complete, a spokeswoman said.
Should the 23-year-old receive a standard two-year suspension, it would prevent him defending his world title next year and seriously hamper his preparations for the 2012 Olympics.
"I am disgusted by this entire episode," USA Track & Field (USATF) chief executive Doug Logan said in a statement.
Merritt won individual 400 metres gold at the 2008 Olympics and 2009 world championships and led the US to victory in the 4x400 metres relay in both competitions.
His victory by almost a second over defending champion Jeremy Wariner at the Beijing Games was the largest winning margin in the event for over 100 years.