Pantani, who competes for the Mercatone Uno team, said he refused to answer the prosecutor's enquiries, but added he he had handed over a large number of documents, which he expected to clear his name.
Pantani, who was in the office for only a few minutes, was recently cleared of doping charges by the Italian Olympic Committee after failing a blood test during the Giro d'Italia, or Tour of Italy, in June. He was disqualified from the Giro two stages from the finish, when a second consecutive victory was well within his grasp.
Pantani, who has repeatedly denied using performance-enhancers, said he had exercised his right not to speak.
Prosecutors last month ordered DNA tests, apparently reviewing the handling and outcome of the random blood check that led to his exit from the Giro.