Jamaican sprinter Asafa Powell has been banned from the sport for 18-months after testing positive for a banned substance.
The former 100m world record holder said he took the stimulant unwittingly in a supplement given to him by his coach.
His coach Chris Xuereb denies the claim.
Powell tested positive at the Jamaican National Championships in June last year.
His former training partner Sherone Simpson, an Olympic relay gold and silver medal winner, was also banned for 18-months.