The witness, Gaspare Spatuzza testified Friday to a court in Turin that in 1993 he was told by his boss that the mob had made a deal with Berlusconi that would provide unspecified benefits to the Mafia.
Reports of Spatuzza's allegations have been swirling for days. But Berlusconi denied any link to the Mafia.
It is completely logical the Mafia would use its members to make statements against the prime minister of a government that has acted in a determined and concrete way against organized crime, said his spokesman Paolo Bonaiuti after Spatuzza spoke.
Our government has arrested eight Mafiosi a day. It has arrested 15 of the 30 most wanted fugitives. It has confiscated an average of 8 million euros from the mafia a day for a total of 5.6 billion euros, said Bonaiuti in a statement.
It's all false. And of course Berlusconi is completely calm about it too. He's more afraid of his wife than Spatuzza, joked Senator Marcello Dell'Utri referring to Berlusconi's current divorce proceedings.
Berlusconi has threatened to sue newspapers that reported he was being investigated and that the mob had a stake in his business.
But the suspicion of Mafia links could damage his standing more than all the fraud and corruption cases, one of which was due to reopen on Friday in Milan, with Berlusconi accused of bribing British lawyer David Mills with $600,000.