Prosecutors are investigating top clubs, referees and officials for suspected match-fixing in the biggest scandal to hit Italy since the 1980s.
Turin-based Juventus are Italy's most successful club
Two senior officials of Juventus, Italy's most successful club, are among 41 people under formal investigation.
Six-times European champions AC Milan as well as Lazio feature in the probe of 19 league games from last season.
In Rome, police searched the soccer federation's offices and those of the referees' association.
Referee Massimo De Santis, who will take part in next month's World Cup in Germany, is being investigated in the probe.
The crisis led incoming Prime Minister Romano Prodi to suggest that a political 'commisar' be put in charge of the Italian Football Federation (FIGC).
Franco Carraro resigned as FIGC president on Monday and is also under investigation by Naples magistrates.
Carraro responded to reports earlier this week that he was under investigation by saying: "I am absolutely calm because I know I have always acted correctly.
"Over the years I have featured in many investigations from magistrates and I have always been cleared or acquitted."
The worlds of business and politics are closely linked to Italian football - former prime minister Berlusconi is owner of AC Milan while the powerful Fiat-owning Agnelli family effectively control Juventus through a holding company.
MATCH-FIXING PROBE MUSHROOMS
4 May: Intercepted phone conversations between Juve's Luciano Moggi and Pierluigi Pairetto, a former member of the federation's refereeing commission, published
8 May: Italian Football federation president Franco Carraro resigns
11 May: Federation vice-president Innocenzo Mazzini resigns
11 May: Entire Juventus board resigns
Leading Italian businessman Diego Dalle Valle, owner of the luxury goods firm Tod's and honorary president of Florence club Fiorentina, was also named on Friday along with his brother Andrea.
Juventus general manager Luciano Moggi and CEO Antonio Giraudo are at the centre of the scandal which was triggered by the publication of telephone taps of them discussing refereeing appointments with senior federation officials.
On Thursday, the board of directors of Juventus resigned en masse ahead of a shareholders' meeting on 29 June.
Turin magistrates have put Giraudo under investigation for possible false accounting relating to transfer dealings.
Magistrates in Rome are examining the operation of the GEA management company, which controls almost 200 players and coaches and is headed by Moggi's son Alessandro.
Juventus are strong favourites to win their 29th Italian title on Sunday's final day of the season, although the status of last season's win now depends on the outcome of the investigations.
If Juventus were to be found guilty of "sporting fraud", they could be stripped of their title win and face demotion to the second tier Serie B.
In the last major scandal to hit Italian football, AC Milan and Lazio were demoted to Serie B in 1980 following a match-fixing and illegal gambling investigation.