The Luxembourg rider and RadioShack Nissan Trek team leader denied taking any banned substances and has requested that a B sample be tested, as the Associated Press reported.
“If this analysis confirms the first result, a complaint will be filed against an unspecified person for poisoning,” Schleck said Wednesday in a statement.
Schleck, 32, who finished third in last year’s race, was in 12th place overall, 9 minutes 45 seconds behind leader Bradley Wiggins of Britain.
The RadioShack Nissan Trek team pulled Schleck out of the competition and said he would be suspended if the second sample confirms the first result.
“We have faith in Frank, but we can’t explain,” team spokesman Philippe Maertens said.
U.S. women’s soccer goalkeeper Hope Solo was issued a public warning earlier this month when she tested positive for a banned diuretic she took as “medication prescribed by (her) personal doctor for pre-menstrual purposes.” The substance, Canrenone, was classified as a “specified substance,” and she was not suspended.
But diuretics like Xipamide are often used to mask performance-enhancing drugs.
Schleck’s younger brother, Andy, was awarded the 2010 Tour de France title after Alberto Contador was stripped of his title due to a positive drug test.
Thomas Voeckler claimed another victory and the polka-dot jersey in Wednesday’s 16th stage with an impressive showing across four grueling climbs in the Pyrenees. Wiggins finished more than seven minutes back but maintained his overall lead. Defending champion Cadel Evans struggled, falling into 12 place overall and out of title contention.