Double world sprint champion Kelli White has vowed to fight to retain her medals despite testing positive for a stimulant.
White claims she took the drug to treat a sleeping disorder
The International Association of Athletics Federations (IAAF) said this week that it did not accept White's explanation for her positive test for modafinil and had referred the matter to the US anti-doping agency.
White, who tested positive after winning the 100m on 24 August, said she took the prescribed medication to combat narcolepsy.
"I'm still going to fight to keep the medals," said White. "I still think there is a chance that I will be able to keep my medals."
Modafinil, though not yet on the IAAF's banned list, is closely related to other drugs which are.
White, the first American to win the sprint double, is still able to compete at this weekend's IAAF Grand Prix Final in Monaco.
"I'm in great shape and I have worked really hard to get where I am, so it will be a great disservice to myself not to
consider running," said the 26-year-old.