Olympic discus thrower Traves Smikle is the latest Jamaican athlete to confirm he is being investigated for doping.
Smikle said in a statement late Thursday that his urine sample at the Jamaican trials last month revealed an adverse analytical finding.
He says he did not knowingly or willfully take any banned substance and has requested an analysis of the "B" sample.
Smikle says: "I am very saddened and surprised by these findings as I have never attempted to cheat and have always considered myself an ambassador for the sport and a strong supporter of drug testing."
Former 100-metre world record holder Asafa Powell and Olympic relay gold medalist Sherone Simpson tested positive for the stimulant oxilofrone at the Jamaican nationals.
Discus thrower Allison Randall and another unnamed athlete also had positive tests at the meet.