Italy has been rocked by yet another investigation into sporting fraud, with two former Azzurri internationals under scrutiny in the latest allegations
The Italian law enforcement agency raided Gattuso's house in Gallarate on Tuesday morning, with fellow former Italy international Cristian Brocchi - previously of Milan, Inter, Fiorentina and Lazio - also part of the inquiry, along with Claudio Bellucci and Davide Bombardini.
Gattuso and Brocchi are under investigation for possible ties to a criminal organisation that attempted to fix the outcome of up to 90 games in Serie A, Serie B and Lega Pro between 2009 and last season, as well as engaging in sporting fraud.
"Gattuso and Brocchi were connected to the case by the use of phone taps," head of investigation Roberto Di Martino said at a press conference on Tuesday.
Four people were arrested on Tuesday morning in an investigation relating to a previous inquiry which resulted in high-profile figures such as Giuseppe Signore, Cristiano Doni and Stefano Mauri receiving footballing bans.
"The four people arrested are Salvatore Spadaro, Francesco Bazzani, Cosimo Rinci and Fabio Quadri, whom are suspected of helping connect fixers to players," Di Martino continued.
"There have been approximately 30 games in Serie where there has been contact between the arrested people and players or coaches linked to the clubs that were playing in the ensuing days."
Tuesday's arrests were carried out in Milan, Bologna, Rimini and Messina.