Former 100-meter world-record holder Asafa Powell and Jamaican teammate Sherone Simpson each have tested positive for banned stimulants, according to their agent.
Paul Doyle told The Associated Press on Sunday that they tested positive for the stimulant oxilofrine at the Jamaican championships and were just recently notified. The news came the same day that American 100-meter record holder Tyson Gay revealed that he also failed a drug test.
"I want to be clear in saying to my family, friends, and most of all my fans worldwide that I have never knowingly or wilfully taken any supplements or substances that break any rules," Powell said in a statement. "I am not now -- nor have I even been -- a cheat.
"My team has launched an internal investigation and we are cooperating with the relevant agencies and law enforcement authorities to discover how the substance got in my system. I assure you that we will find out how this substance passed our rigorous internal checks and balances and design systems to make sure it never happens again."
The IAAF said the credibility of the sport's anti-doping program was "enhanced, not diminished" with the news of Sunday's positive tests.
IAAF spokesman Nick Davies said the sport's governing body does not comment on pending cases, but added that the fight against doping is improved "each time we are able to uncover a new case."
"The IAAF's commitment to anti-doping in athletics is unwavering because we have an ethical obligation to the majority of athletes who believe in clean sport," Davies said in a statement Monday. "The fact that we are able to detect and remove from the sport athletes who have breached our anti-doping rules should be seen in this context."
Powell helped the Jamaicans to the 400-meter relay gold medal at the 2008 Olympics and was the last man to hold the individual 100 record before countryman Usain Bolt broke it earlier that year.
Simpson won Olympic gold in the women's 400 relay in 2004 and silver in 2012, along with an individual silver in the 100 in 2008.
"They're devastated," Doyle said in a phone interview. "I'm optimistic that Asafa's and Sherone's names will be cleared. It is a stimulant ban, which I hate to call any infraction minor -- any positive test is major, in my opinion -- but at the same time it was something that was inadvertent. Hopefully, through our investigation and all that, we'll be able to show it was unintentional."
These doping positives come a month after another Jamaican Olympic champion, Veronica Campbell-Brown, tested positive for a banned diuretic.
Powell said the results left him "completely devastated."
"I accept the consequences that come with this finding -- after all there is only one Asafa Powell," he wrote in the statement. "My fault here however is not cheating but instead not being more vigilant. I want to reiterate that in my entire career as an athlete I have never sought to enhance my performance with any substance. It is not apart of who I am or what I believe in."
Simpson also released a statement, saying: "This is a very difficult time for me. ... My team and I will try to do everything we can to get this issue dealt with as best as we can."
Doyle said it's too early to say whether Powell or Simpson will be able to compete at the world championships in Moscow next month. Powell did not finish in the top three at last month's nationals to qualify for worlds, but possibly could participate as a member of the 400 relay. Simpson earned a spot by finishing second behind Kerron Stewart in the women's 100.
"We'll see if things can get cleared up before worlds," Doyle said.
Information from The Associated Press was used in this report.