Italian cyclist Franco Pellizotti provided evidence at the Court of Arbitration for Sport in a case that could effect cycling's anti-doping biological passports.

Pellizotti has not raced since May when the International Cycling Union said his biological passport showed irregular blood readings, which can suggest doping.

The UCI cited irregularities from a sample taken after Pellizotti placed third in the 2009 Giro d'Italia and before the 2009 Tour de France, in which Pellizotti won the mountains classification.

The Italian Olympic Committee recommended a two-year ban. But its anti-doping court exonerated him last October citing lack of proof.

The UCI appealed that ruling to the CAS, and Pellizotti is seeking damages from the sport's governing body. Pellizotti has denied taking banned drugs.

Expert witnesses for the UCI include the head of the World Anti-Doping Agency laboratory in Lausanne, Switzerland. The lab devised and manages the passport program.

The passport uses an individual blood profile, designed to catch drug cheats by revealing changes in a cyclist's blood over time without needing to find traces of banned drugs.

About 850 professional racers have given blood samples for their passport. Suspicious profiles are presented to a UCI-appointed independent panel of nine experts that advises if the results and the rider's explanation can be justified medically or scientifically.

Pellizotti was favored for the 2010 Giro d'Italia, but was provisionally suspended before the race. He has since left the Liquigas team.

He is the fourth rider to come before sport's highest court in a case that will test the validity of the passport program.