Former AC Milan and Italy midfielder Gennaro Gattuso was placed under investigation for match-fixing Tuesday and four more people were arrested in an early morning police sweep in Italy.

Cremona prosecutor Roberto Di Martino, who has been leading the Last Bet operation for three years, confirmed to The Associated Press that Gattuso and retired Milan and Lazio player Cristian Brocchi were allegedly part of a ring that fixed Serie A and other Italian matches at the end of the 2010-11 season.

The four people arrested were Salvatore Spadaro, Francesco Bazzani, Cosimo Rinci and Fabio Quadri; each of whom allegedly helped connect fixers to players, Di Martino said.

Gattuso and Brocchi face charges of criminal conspiracy and sports fraud, according to the ANSA news agency.

“Gattuso and Brocchi were connected to the case by the use of phone taps,” said Di Martino, who could not confirm the exact charges.

Gattuso, who was on the Italy squad that won the 2006 World Cup, was fired as Palermo manager in September. Brocchi is currently coaching in AC Milan’s youth programme.

Police said in a statement that the arrests were carried out in Milan, Bologna, Rimini and Messina.

The investigation has resulted in more than 50 people being arrested in Italy since mid-2011, with matches under investigation by prosecutors in Cremona, Bari and Naples.

It has resulted in lengthy bans for former Lazio captains Giuseppe Signori and Stefano Mauri, as well as former Atalanta captain Cristiano Doni. Several clubs have also had points deducted.

Prosecutors have detailed an extensive match-fixing ring stretching as far as Singapore and South America that was allegedly in operation for more than 10 years.

The arrests of 14 people in Singapore in September was hailed as a major breakthrough in the fight against corruption in football, with the global network’s suspected mastermind among those taken into custody.

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