Former Italian PM Silvio Berlusconi is being investigated for alleged involvement in a series of mafia bombings in 1993, his lawyer said.
Prosecutors opened a probe when a jailed mafia boss caught on a wiretap hinted that Berlusconi was involved.
It is the third time Berlusconi has been investigated for a possible role in the bombings in Rome, Milan and Florence which left 10 people dead.
The first two investigations were dismissed due to lack of evidence.
It is believed that the 1993 attacks were carried out in revenge for the arrest of mafia boss Toto Riina. Italy had also recently brought in harsh anti-mafia laws.
Giuseppe Graviano is serving a life sentence for his role in the bombings and for the murder of two anti-mafia judges and an anti-mafia priest.
He is reported to have said on the wiretap that Berlusconi encouraged the violence for his own political ends.
He claimed that the former prime minister had urged him to commit acts of violence against the state, AFP reports.
Berlusconi's lawyer, Niccolo Ghedini, dismissed the latest probe as "the umpteenth investigation that will shortly be shelved, like the previous ones".