ROME - An Italian magazine released more tapes Thursday of purported conversations between Silvio Berlusconi and a high-class prostitute, keeping up the pressure in the sex scandal engulfing the Italian premier.

L'Espresso, a leftist news weekly, has been releasing the recordings of the alleged conversations between Berlusconi and the escort over several days in an apparent effort to embarrass the conservative premier.

Berlusconi's lawyer disputed the authenticity of the tapes when the first batch came out. Berlusconi broke his silence Wednesday when he joked that he was "no saint."

The woman at the centre of the scandal, Patrizia D'Addario, has said she spent the night of Nov. 4 with Berlusconi after attending a dinner party at his Rome residence.

In the tapes released Thursday, a woman identified as D'Addario is heard discussing details of a sexual encounter with a man who the magazine says is Berlusconi. She is heard praising the man's sexual performance.

D'Addario has said she recorded her encounters with the premier. She says she came forward because Berlusconi reneged on a promise to help her with a real estate problem she was having.

While the voice on the tapes sounds like the premier's, The Associated Press has not independently verified that Berlusconi is the speaker.

The 72-year-old Berlusconi in the past has denied he ever paid anyone for sex, and has called the allegations "trash" meant to smear him. His lawyer, Niccolo Ghedini, said Monday that the tapes were "without any merit, completely improbable and the fruit of invention."

Foreign Minister Franco Frattini described the allegations as "absolutely" not true. In an interview Thursday with the BCC, the minister stressed that the premier isn't under investigation in the scandal.