Italian authorities have arrested 11 people in a probe of corruption linked to the Sicilian Mafia and construction contracts for Milan's Expo 15 fair.
Milan Judge Maria Cristina Mannocci wrote that company administrators, consultants and accountants closed their eyes to corruption and mob links relating to the fair that was a point of pride for premier Matteo Renzi.
Prosecutors told reporters in Milan they seized €5m in assets, including €400,000 in cash found in a truck travelling from the Milan area to Sicily.
Anti-Mafia prosecutors allege that the cash was being laundered.
Among the alleged crimes are false bookkeeping, tax evasion, money-laundering, embezzlement and, for two of the arrested suspects, helping Cosa Nostra.
According to prosecutors, false expense receipts were issued to cover illicitly gained cash in need of laundering.
Prosecutor Francesco Greco said much of the money was laundered abroad, and an investigation of that angle was still ongoing.
Authorities suspect corruption tainted the awarding of some sub-contracts for the construction of some Expo pavilions.
Prosecutors have warned for years that mobsters from the Calabria-based 'Ndrangheta syndicate are infiltrating businesses in northern Italy, the country's industrial and financial heartland.
Milan prosecutor Ilda Boccassini said this probe also revealed that the Sicilian Mafia, known as Cosa Nostra, was active in the north. Investigators cited suspects' intercepted phone conversations.
She stressed that investigators found no wrongdoing by top administrators of Expo's or Milan's industrial fair organization.
In an unrelated scandal in Rome, opposition party leaders in Parliament demanded the resignation of interior minister Angelino Alfano, whose centrist party belongs to Mr Renzi's governing coalition.
Mr Alfano's father is reportedly involved in a probe of alleged kickbacks, embezzlement and favouritism in hiring for Italy's postal agency.