Powell - but not Bolt - among Jamaican test failures
Former world record holder Asafa Powell is among five Jamaican athletes to have failed drugs tests at their recent national championships.
On the day it was revealed that American Tyson Gay had also failed a drugs test, forcing him out of next month's World Championships, Powell was confirmed as the most profile of a number of Jamaicans to have also fallen foul of drug testers.
Powell's management company admitted on Sunday that the 30-year-old had tested positive for a banned substance, as had 4x100m relay medallist Sherone Simpson.
Both athletes were found to have traces of the stimulant oxilofrine in their sample. Powell denied knowingly committing any wrongdoing, and vowed to get to the bottom of the situation.
"I want to make clear that I have never knowingly or wilfully taken any supplements or substances that break any rules," Powell said in a statement. "I am not - nor have I ever been - a cheat."
Olympic gold medal-winning relay runner Nesta Carter was also reported in some quarters to have been among the group who failed a test - while Veronica Campbell-Brown admitted to an indiscretion last month.
Powell has an illustrious record, despite developing a reputation for falling to produce his best form on the biggest occasion.
He held the 100m world record for almost three years between 2005 and 2008, although his personal best of 9.72 seconds came only after Usain Bolt had rewritten what many thought sprinters were capable of.
Powell has broken the ten-second barrier more times than any other athlete - but has only one major gold medal, at the 2006 Commonwealth Games to his name. He twice took bronze at the World Championships, in 2007 and 2009, but failed to finish among the individual medals at any Olympic Games.
His only Olympic gold came in the 4x100m in Beijing.