The International Cycling Union has requested disciplinary proceedings against last year's Giro runner-up Franco Pellizotti of Italy after finding suspicious data in his biological passport.
The sport's governing body has also asked for measures to be taken against Spain's Jesus Rosendo Prado and Slovenian Tadej Valjavec, 10th overall in the 2008 Tour de France, for the same reason.
Since January 2008, the UCI has collected blood samples from all professional riders to create a medical profile to be compared with data registered in doping tests.
Pellizotti, who also won the polka dot jersey for the best climber in last year's Tour de France, is set to miss the Giro d'Italia starting in Amsterdam this Saturday. Pellizotti's team, Liquigas, made no comment.