Prosecutors in Naples have ordered the search of dozens of football club offices as part of a tax fraud investigation relating to player contracts.
Financial police were executing search warrants today at the offices of about 20 Serie A clubs, including AC Milan, Juventus and Lazio, in addition to clubs in lower leagues.
A statement by Naples prosecutors said some foreign clubs were also part of the investigation, but they did not identify them.
Prosecutors said the clubs are under investigation for alleged conspiracy to avoid payment of "huge amounts of money" to tax authorities during the transfer of players.
Italian finance police have seized documents from 41 football clubs, including 18 teams from Serie A, as part of a probe into tax and money laundering.
Serie A side Juventus have been fined €4,000 by the Italian league after its supporters targeted AC Milan forward Mario Balotelli with racist chants during a win over Catania on Sunday.
Lazio were also fined €10,000 by Italian footballing authorities after its supporters displayed an offensive banner against UEFA's President Michel Platini.