Lazio president Claudio Lotito drives away from the hearing

The trio, along with Juventus, face relegation and fines if found guilty of sporting fraud.

Juventus' lawyer Cesare Zaccone has already said his clients could settle for relegation and points deduction as "an acceptable punishment".

"Lazio are innocent," said lawyer Gian Michele Gentile.

The scandal broke in May with the publication of transcripts of telephone conversations between former Juventus general manager Luciano Moggi and Italian Football Association officials, discussing refereeing appointments in the 2004-05 season.

Respect for the rules is in Milan's DNA Milan lawyer Marco De Luca

A tribunal in Rome is investigating charges that the clubs, their management, football officials and referees tried to influence the outcome of matches by interfering with the appointment of referees.

It is due to deliver its judgement on Monday, the day after Italy play in the World Cup final.

Lawyer Marco De Luca, representing Milan vice-president lawyer for Adriano Galliani, the vice-president of six-times European champions Milan, also protested his clients had done nothing wrong.

"Respect for the rules is in Milan's DNA," he said.

The sports tribunal will not hand out penal sentences.

A separate magistrates' investigation in Naples has yet to decide whether to press criminal charges against some of the individuals accused.