The long-running trial, which features former Juventus general manager Luciano Moggi as one the defendants, is the criminal equivalent of the sporting tribunal which took away the Turin side's 2005 and 2006 scudettos for procuring compliant referees.
Asked by a lawyer how many trophies he had won with Juve, Del Piero told the court: "It depends. I also count the two scudettos taken away. While I have been playing, I believe that every side that have won a championship have deserved it."
The former Italy forward, who has spent almost his entire career with Juventus, equalled Giampiero Boniperti's Juve record of 178 Serie A goals on Sunday and usually avoids controversy.
However, the soft-spoken 35-year-old is backing Juve's campaign for Inter Milan to have the 2006 league title which was awarded to them also stripped after new evidence suggested their rivals could have also been implicated in the scandal.
European champions Inter, bidding for their sixth straight Serie A title this season, deny wrongdoing but the Italian soccer federation has taken fresh phone tap evidence from the criminal trial in Naples which it is examining.
Several other Italian players and referees were heard as witnesses on Tuesday.
