Patrizia D'Addario, who claims that she and other women were paid to attend Berlusconi's private parties, said Thursday she had secretly recorded video footage of her encounters in the prime minister's Rome residence.
The Times said the 42-year-old D'Addario, who also worked as an escort girl, said that the footage showed her standing in front of a mirror in a bedroom with a framed photograph of Berlusconi's wife Veronica Lario.
She said she had made the recordings "so that nobody could deny I had been there".
Berlusconi, 72, is already being sued for divorce after his wife publicly objected to him attending the 18th birthday party model Noemi Letizia, accusing him of "frequenting minors".
Police said they were checking the footage for authenticity, the Times said.
-IANS