Fränk Schleck (RadioShack-Nissan) has appeared before the Disciplinary Committee of the Luxembourg Anti-Doping Agency (ALAD) late on Wednesday, reports l'essentiel.lu.
Schleck tested positive for the diuretic Xipamide at an in-competition test at the Tour de France on July 14, 2012.
The committee will now determine if Schleck will be subject to any sanctions with a decision set to be handed down in a matter of weeks.
When the 32-year-old's B-sample confirmed the presence of Xipamide on July 20, Schleck maintained that he had "done nothing wrong" and that he had been the victim of poisoning.
"The medical world states that this product, when performing in extreme conditions such as in a cycling tour, is very dangerous; it can even cause death," he said in a statement. "Therefore I really need to find the cause that clarifies how this product ended up in my system: since I didn't take anything, I assume it must have been given to me by someone, or it could have happened through an accidental contamination, or it could be caused by something that is not yet known to me since we are still undertaking a number of analyses."