Luxembourgish rider Frank Schleck plans to file a formal complaint of poisoning if his B sample confirms the presence of the banned diuretic Xipamide at the Tour de France. After testing positive Tuesday, Schleck voluntarily withdrew from the Tour but maintained his innocence. "I categorically deny taking any banned substance,” Schleck said. “I have no explanation for the test result and therefore insist that the B sample be tested, which is my right. If this analysis confirms the initial result, I will argue that I have been the victim of poisoning." Xipamide falls under the “specified substances” portion of the World Anti-Doping Code, meaning that Schleck will have the opportunity to argue that he ingested the drug without the intention of enhancing performance. If WADA accepts this argument, he would face only a reprimand rather than a long period of ineligibility. Xipamide increases the frequency of urination and is typically used to mask other drugs.