Things can't be all that clean either. According to a recently released annual report by Confesercenti, a major business association in Italy, the four main mafia groups in the country together take in about $126B a year (yes, that's more than Italy's largest companies), amounting to an astonishing 7% of Italy's gross domestic product. Most of the money is "earned" through drugs, extortion, loan sharking and prostitution, though the estimate excludes the revenues from the sale of drugs.
Is it naive to believe that some of that money isn't derived from gambling and match-fixing?
Organised crime does pay in Italy - to the tune of €90bn [Guardian]
Italy's in the Global Fortune 500 [CNN]