The 32-year-old tested positive for the banned diuretic Xipamide at the Tour de France in July and has not raced since.
Schleck, who pulled out of race immediately and has always denied knowledge of taking the drug, spent two hours in front of the Luxembourg Anti-Doping Agency on Wednesday night.
It was the third time the Luxembourg rider has appeared in front of ALAD, following hearings in August and October.
A final decision is not expected for another six weeks.
"I explained myself again that I was not at fault," Schleck told AFP. "The investigation is continuing but it's not over."