Juventus trainer Antonio Conte is under investigation regarding a match-fixing scandal that has already seen 11 team-mates and former players arrested.
Nineteen people have been detained in total.
Conte has just steered Juventus to winning the Serie A Championship for the first time since the team was relegated six years ago after previous match fixing problems.
One of those detained by police is the captain of Lazio, Stefano Mauri. Authorities confirmed they are also holding former Genoa midfielder Omar Milanetto.
Three people close to the players and five in Hungary have been arrested in the investigation into an international betting ring run by Singaporean Tan Seet Eng, who was detained by police in December.
As the Italian national team meets for training ahead of the Euro 2012 tournament, authorities have been questioning the team at its ground.