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 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.