The Olympic and world 400 metres champion LaShawn Merritt has failed three doping tests for a banned substance and accepted a provisional suspension.
His attorney says 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 statement says Merritt had used the product, which contained DHEA and pregnenolone, following the 2009 season.
Merritt, who upset favourite Jeremy Wariner to win the Olympic 400 metres title in Beijing two years ago, was not notified of the positive tests until March.