The Italian Football Federation (FIGC) confirmed that Mauri and Milanetto have been held over allegations of "criminal association and sporting fraud".
Officers are searching more than 31 homes in Italy and abroad, including those of coaches and players of clubs in Serie A, Serie B and lower divisions.
Police also arrived on Monday morning at Italy's training ground in Coverciano, Florence, to question former Genoa defender Domenico Criscito, who now plays for Zenit St Petersburg.
A statement from the FIGC read: "As part of the investigation carried out by prosecutors of Cremona regarding match-fixing, prosecutor Guido Salvini has issued 19 procedures: 14 people arrested (including Mauri and Milanetto), 31 home searches and two people questioned.
"Police agents also arrived to Italy's training ground in Coverciano this morning to hand a notification of impeding investigation to defender Domenico Criscito, who is investigated for acts that would have taken place while he was a Genoa player."
The operation is part of an investigation called "Last Bet" carried out by prosecutors in Cremona which focuses on 33 games over the past two seasons, the majority of which were in Serie B.
Earlier this month, the FIGC released a comprehensive 48-page list naming 22 clubs along with 61 individuals that have been reported to the football authorities in connection with a match-fixing ring and betting investigation.
Seventeen people were arrested by Italian police last year, including Atalanta captain Cristiano Doni. Atalanta, who had been promoted to Serie A at the end of the 2010-11 season, began the recently completed campaign with a six-point deduction as punishment for match-fixing.
Doni was banned from football for three and a half years by the FIGC's disciplinary committee.