NAPLES, Italy -- The biggest scandal to hit Italian football in 20 years has mushroomed after prosecutors revealed they were investigating top clubs, referees and officials for suspected match-fixing.

Two senior Juventus officials -- general manager Luciano Moggi and CEO Antonio Giraudo -- are among 41 people who are now formally under investigation.

AC Milan and Lazio also feature in a total 19 Serie A matches from last season which investigators suspect could have been rigged.

In Rome, police searched both the football federation's offices and those of the referees' association.

Referee Massimo De Santis, who will take part in next month's World Cup finals in Germany, is being investigated in a probe in Naples -- prosecutor Giovandomenico Leparo confirmed to CNN.

The Naples magistrates are looking into suspicions of "criminal association" and "sporting fraud." Investigations by public prosecutors do not necessarily lead to criminal charges.

The crisis has led incoming Prime Minister Romano Prodi to suggest that a political 'commisar' be put in charge of the federation (FIGC).

Prodi, who won last month's elections, put forward Gianni Letta, an ally of former prime minister Silvio Berlusconi and the center-right's failed candidate for president, as an ideal head of the federation should Italy's Olympic Committee decide effectively to take control of it.

Franco Carraro resigned as FIGC president on Monday and is also under investigation by Naples magistrates.

In Italy, the worlds of business and politics are closely linked to football -- Berlusconi is owner of AC Milan while the powerful Fiat-owning Agnelli family effectively control Juventus through a holding company.

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.

Tod's and Fiorentina declined to comment. On Thursday, Fiorentina issued a statement saying the Della Valle family respected the rules of the sport.

Moggi and Giraudo are at the center 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 June 29.

Turin magistrates have put Giraudo under investigation for possible false accounting relating to transfer dealings.

Shares in Juventus dived for a second day and were down seven percent at 1.97 euros in midday trade on Friday. They have lost some 15 percent of their value since Wednesday's close.

As well as the Naples investigation, 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.

Amid the off-field storm, Juventus could 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.

(via CNN)