(ANSA) - Palermo, September 18 - Prosecutors in Palermo are probing the wife of Marcello Dell'Utri for aggravated money laundering as part of investigations into alleged extortion by the centre-right Senator and one-time aide of former premier Silvio Berlusconi. Dell'Utri is thought to have received around 40 million euros from Berlusconi over 10 years. Investigators believe the money served to buy the lawmaker's silence about alleged relations with the Sicilian mafia or protection from it. Roughly 15 million euros of the 21 million paid by Berlusconi for Dell'Utri's sumptuous villa on Lake Como in northern Italy reportedly ended up in the account of Miranda Ratti, the Senator's wife, in early March. She then transferred part of the sum to an account in the Dominican Republic, where Dell'Utri is thought to have been at the time. The transfer was made the day before Italy's supreme Court of Cassation ordered a retrial of the former Berlusconi aide for allegedly helping the Mafia on grounds that his legal rights had not been respected in an earlier appeal, but also said there was evidence the suspect had acted as an intermediary with the mafia for the ex-premier, handing on "substantial sums" of money for protection.