KINGSTON - Olympic discus thrower Allison Randall on Monday became the third athlete to confirm a positive drugs test from the Jamaican trials in June following Sunday's revelations by sprinters Asafa Powell and Sherone Simpson.

Randall, who competed at last year's London Games but failed to make the final, acknowledged receipt of the Jamaica Anti-doping Commission's (JADCO) notification of her adverse finding for a banned diuretic but, like Powell and Simpson, denied knowingly taking a performance-enhancing substance.

"I have not intentionally taken any banned substance. I have been vigilant with everything I consume, so I am extremely shocked and surprised by this incident," Randall said in a statement to Jamaican Radio station RJR 94 FM.

The 25-year-old, who holds the Jamaican discus record with a distance of 61.21 metres, said she did not have the desire or the means to cheat.

Reuters sources said she had tested positive for the banned drug Hydrochlorothiazide, which reduces blood volume.

Powell and Simpson confirmed that they tested positive for the stimulant Oxilofrine (methylsynephrine) while two more Jamaican athletes are reported to have failed tests at the same championships.

American former double world champion Tyson Gay also said on Sunday that he had tested positive for a yet-to-be-revealed substance.