SAINT-DENIS, France (AP) _ Kelli White passed a drug test after winning the 200 meters for her second gold medal at the World Championships, but her earlier positive sample following her victory in the 100 jeopardizes both medals.

Istvan Gyulai, general secretary of the International Association of Athletics Federations, confirmed Sunday the U.S. sprinter's latest doping test was negative.

White won the 100 a week ago and completed the sprint double in the 200 on Thursday, becoming the first American woman to sweep both events at a world championships.

The IAAF said Saturday she tested positive for the stimulant modafinil after the 100 final and risked being stripped of both gold medals if found guilty of a doping offense. She could also face a two-year suspension.

Even though White tested negative after the 200, the IAAF said her positive test after the 100 would be enough to disqualify her from the entire championships and cost her both medals.

``It doesn't change things,'' IAAF spokesman Nick Davies said. ``It's irrelevant. We had a positive sample after the 100 meters. If we disqualify her, we disqualify her.''

Gyulai said, ``It would be wrong to say, `You are doping on Sunday, and you're out,' and then say, `You can win the same medal Thursday at the same championships.' I believe this is an important moral message.''

Gyulai said the IAAF was continuing to investigate the exact nature of modafinil, a prescription medication which White said she used for a sleep disorder.

While not specified by name on the banned list, modafinil is covered under the stimulants category of ``related substances,'' the IAAF said.

Under IAAF rules, the penalty for use of light stimulants, such as ephedrine, is disqualification and a public warning. For harder stimulants, such as amphetamines, the sanction is disqualification and a two-year ban.

Gyulai said IAAF doping officials expect it could take four or five days to determine how to classify modafinil. After that, he said, the IAAF would have three options: accept her explanation and consider clearing her on grounds of ``exceptional circumstances''; disqualify her and give her a warning; or disqualify her and recommend a two-year ban.

At a news conference Saturday, White denied ever taking a substance to enhance her performance. She said she took the medication only to treat narcolepsy and had ``no idea'' it contained a banned substance.

White said she didn't apply for a medical waiver or include the medication on her doping control form because it wasn't named on the prohibited drug list.

``Because I know that I did nothing wrong and sought no advantage over my competitors, I am confident that things will work out in the end,'' White said.