Smikle said in a statement late yesterday that his urine sample at the Jamaica trials last month revealed an adverse analytical finding. He said he did not knowingly or willfully take any banned substance and he has requested an analysis of the B sample.
"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," said Smikle, a political science major at the University of the West Indies.
Powell has said he did not cheat, while the trainer for both athletes has denied giving them performance-enhancing drugs as others have alleged.
Discus thrower Allison Randall and another unnamed athlete also returned positives for banned substances at the same meet.
Also Read
In addition, Olympic champion Veronica Campbell-Brown tested positive for a banned diuretic in May.
The doping scandal has rattled Jamaica, an island of 2.7 million people that prides itself on producing track stars, and which has won 28 medals in the last three Olympics.
The commission recently said it has conducted 504 in-competition tests and 356 out-of-competition tests since it was launched in May 2009.