By his own admission, the second-fastest man in history, Tyson Gay of the US, has stumbled big time. "I don't have anything to say to make this seem like it was a mistake," Gay was reported as saying when news broke that he had tested positive for a banned substance. Also testing positive is the fourth-fastest man in history, Asafa Powell of Jamaica. Four other Jamaican athletes also failed dope tests.
Powell tested positive for oxilofrine – an amphetamine chemically related to ephedrine, and originally developed to treat low blood pressure. What Gay tested positive for has not been officially revealed so far.
The positive results were on the basis of 'A' samples. Second 'B' samples remain to be tested. Neither athlete will compete at the world championships next month in Moscow.
Wilhelm Schänzer, director of Germany's official dope testing laboratory at the German Sports University in Cologne, says adulterated dietary supplements might be to blame.
David Cowan, head of the Drug Control Centre at King's College London, agrees. "Oxilofrine is known to be available in dietary supplements, especially those used mainly for weight loss," he says.
Schänzer's lab analysed 634 supplements from 13 countries and found that 15 per cent contained banned substances. He says there have been other recent positive tests for oxilofrine. Following a bout in Germany on 1 February, the Australian boxer Sam Soliman was found to have taken oxilofrine, but blamed it on a supplement drink called "Black Bombs".
Into hyperdrive
Another case in 2010 involved Brazilian cyclist Flavia Oliveira, who blamed her positive test for oxilofrine on a dietary supplement called Hyperdrive 3.0+.
"It's definitely feasible for someone to inadvertently dope by taking a supplement that's either accidentally or deliberately doped," says Cowan. "Often labelling is poor and we have found illegal substances in supplements that are not labelled at all," he says.
Powell has protested his innocence. "I have never knowingly or wilfully taken any supplements or substances that break any rules," he said on Twitter. Gay put his result down to a .
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