SANTO DOMINGO, Dominican Republic (AP) – U.S. sprinter Mickey Grimes tested positive for the stimulant ephedrine and will be stripped of two gold medals he won at the Pan American Games.

The Pan American Sports Organization said Tuesday the doping test conducted in a Montreal laboratory showed Grimes had 13.7 micrograms per milliliter of ephedrine in his system. The legal limit is 10.

“I understand that athletes need to take responsibility for everything we put in our bodies,” Grimes said in a statement released through the U.S. Olympic Committee. “I made a mistake and I know that my action carries with it a penalty.

“I sincerely regret letting down the U.S. delegation and my country, and I look forward to representing my country in the future.”

An ephedrine positive carries a maximum penalty of disqualification from the meet and a public warning. Gimena SaldaIna, PASO’s executive secretary, said the U.S. 400-meter relay team, on which Grimes ran the opening leg, would be stripped of its gold medal, too, because Grimes became an ineligible athlete after testing positive for the early dash.

The 26-year-old Grimes won the 100 meters in 10.10 seconds on Aug. 6.

Ephedrine, commonly found in over-the-counter dietary supplements and cold medications, is ephedra’s active ingredient and is on

the list of prohibited substances.

Last month, the Food and Drug Administration said it was looking into banning ephedra, an herbal stimulant used to lose weight and boost athletic performance.

In February, the FDA ordered labels to be put on products with ephedra warning of the possibility of heart attacks, strokes or death. The move came two weeks after the sudden death of 23-year-old Baltimore Orioles pitcher Steve Bechler, who had been taking a dietary supplement containing ephedra.

Scientists and health officials argue the FDA should classify ephedra as a prescription drug to be dispensed only when a doctor approves.

In 2001, Grimes won a world championships gold medal as part of the U.S. 400-meter relay team. He played wide receiver and ran track at Riverside Community College before transferring to Abilene Christian, where he was a defensive back.

After his victory last week, Grimes said: “It’s not Olympic gold or world championship gold, but it’s my first international championship, so I’m happy.”

Local organizers said the positive drug tests would not cast a shadow over the events.

“We will always be concerned by any athlete who appears to be doping,” games secretary general Luis Mejia said. “We have to wait until the games are over to make a complete evaluation. This subject does not affect the quality of the games.”

AP-ES-08-12-03 1634EDT