She has been provisionally suspended by the IAAF pending a hearing, the sprinter said. “I have nothing to hide,” a defiant Fraser said after withdrawing from the Lausanne Diamond League meeting.

The positive test was triggered by her failure to list on a doping form at May's Shanghai Diamond League meeting a painkiller she was given by her coach for a three-day-old severe tooth pain, the 2008 Beijing gold medallist said. “I will go home and have a hearing before my federation in Jamaica,” she added. “I hope they will accept my explanation.”

Both her agent and coach confirmed the sprinter's suspension. IAAF spokesman Nick Davies said they were still waiting for the case to be concluded, but based on the explanation provided by Fraser and her agent, they were ‘disappointed with her carelessness’.

“Athletes must pay more attention to what they ingest as our rules are clear,” he said in an e-mail. Fraser, a role model for Jamaican youth, said she had mixed emotions about the positive. “I take some responsibility because athletes are supposed to be responsible for what they take,” she said. “But I am upset because everybody is starting to assume I am taking drugs. My reputation is ruined somewhat.”Her coach, Stephen Francis, said the punishment for such a violation usually is a public warning. “It is not a performance-enhancing substance or a masking agent,” the coach said.

Fraser was notified of the positive about three weeks ago and told on Thursday she had been provisionally suspended, her agent, Adrian Laidlaw, said in an interview. Only her ‘A’ sample has been tested, Fraser said. “There is no need to test (the ‘B’ sample) because I don't appeal.”

She said she had three teeth filled in Jamaica before flying to Shanghai and had sought help from medical and meeting officials for resulting pain. When their medication did not ease the hurt, she had thought of withdrawing from the Shanghai race, she said. But Francis persuaded her to take a painkiller he was taking for kidney stones, Fraser said. The medication eased the pain, Fraser said, but it caused her to feel weak and run slower than normal in the race.