World 100m champion Torri Edwards may miss the Olympics after testing positive for nikethamide in April.
Edwards faces an anxious wait over her future
The 27-year-old American claims she accidentally ingested the banned steroid in a glucose tablet at a meeting in Martinique in April.
Her manager said: "She believes there are exceptional circumstances that merit an elimination or substantial reduction of the current sanction.
"She has requested a hearing before the American Arbitration Association."
Edwards finished second in the 100m at the US Olympic trials on Saturday but could lose her place in the American team if found guilty of a doping violation.
"Torri is not a drug cheat," insisted her manager, Emanuel Hudson.
"She has never knowingly and intentionally misused any product or drug to gain an
unfair advantage over her competitors."
Under World Anti-Doping Agency rules, Edwards could be suspended for up to two years unless she can prove she inadvertently used the drug.
In that case, she would be given a warning and would lose the results from the meeting where she tested positive.
IAAF spokesman Nick Davies said she is due to face a US Anti-Doping Agency hearing on Monday.
"Her A and B samples have tested positive," said Davies.
Acts mainly on central nervous system
Is a respiratory and cardiovascular stimulant
Formerly used in the treatment of barbiturate overdose
Edwards was awarded the world 100m gold medal from last year after Kelli White, another US sprinter, was stripped of the title in June.
White has been suspended from competition for two years after admitting using steroids and several other banned substances.
Edwards moved from third to second in the world 200m finish when White also lost her gold medal in that event.
The woman who was awarded the gold medal after White's ban, Russia's Anastasiya Kapachinskaya, also subsequently tested positive for a banned substance and is now serving a two-year ban.
Edwards' positive test means that the every athlete on the podium in that world 200m has now failed a dope test.