The call girl who says she spent the night with Italy's prime minister, Silvio Berlusconi, has claimed she became the target of a string of attacks and threats after releasing alleged recordings of their encounters.

In a book about her experiences to be published on Tuesday, Patrizia D'Addario adds a lesbian dimension to the allegations surrounding Italy's billionaire leader.

The 42-year-old said that after she made her allegations, a car tried to ram into hers on a road near her home town of Bari in the south of Italy. She said that she had accelerated and lost control of her car.

"I found myself on the other side of the road, facing the wrong way. It was only by a miracle that I survived," she wrote in an extract from her book published today by a recently launched leftwing daily, Il Fatto Quotidiano.

D'Addario said she had also been the target of an attempted rape and received numerous menacing telephone calls. In one the caller had threatened to abduct and rape her daughter. Her mother had been punched in the face in the street.

In the latest incident, her flat had been broken into. The thieves had taken much of her clothing, her diaries and her computer, but left behind a very expensive television set, she wrote.

The man who accompanied D'Addario to the prime minister's home is under investigation in Bari on suspicion of drug trafficking and aiding and abetting prostitution. Berlusconi is not a suspect in the inquiry and his lawyer has denied that the call-girl's recordings are genuine.

The publication of D'Addario's book will divert public attention back to the affair after a period in which the focus had been on another sex scandal involving the former centre-left governor of the region around Rome. Piero Marrazzo resigned after being filmed taking drugs and having sex with a transsexual.

Last week, a key figure in the affair, a transsexual Brazilian prostitute, was found dead in her flat in the capital. Investigators are treating her death as murder.

D'Addario claims to have visited Berlusconi's private residence in Rome twice last year. On the first occasion, she said, the other guests at the dinner included two lesbians. They "must be at home," D'Addario writes. "They kiss and stroke one another and address the prime minister in a very familiar way."

This has political significance. Many conservative Italians ready to forgive, if not endorse, heterosexual promiscuity will be disconcerted by a claim that their leader's private life extends to lesbianism.

In her book, written with a leading Italian journalist, D'Addario says that the two women were among about 20 at the first party. At one point, they were shown a political documentary including a sequence in which the anthem of the prime minister's party ("Meno male che Silvio c'e", which translates roughly "Thank goodness for Silvio") was played.

"Everyone in the room began to sing and do the [audience] wave. I looked on curiously and my first thought was that I was in a harem … Being an escort, I reckon I have seen a good few things. But I'd missed out on this — 20 women for one man."

Gradisca, Presidente. By Patrizia D'Addario and Maddalena Tulanti. Aliberti Editore.