Nadia Macri, who claims to have had sex with Italy's prime minister, says she has received menacing messages

The car belonging to one of the women who gave evidence to investigators about Silvio Berlusconi's alleged bunga-bunga sessions was set alight at the weekend. Nadia Macri, who claims to have twice had sex with Italy's 74-year-old prime minister, said: "I really don't think that the prime minister has anything to do with my car."

She told reporters she had recently received a number of menacing text messages that she had shown to police after the discovery of the burnt-out car. Berlusconi's lawyers have strenuously denied Macri's allegations and contest her claim that the prime minister's dinners at his house outside Milan led on to orgiastic sessions in a room equipped for pole-dancing.

Another female guest at parties given by Berlusconi had her car set alight in June 2009. Barbara Montereale, a model, was among the witnesses in an investigation into the activities of a businessman who admitted recruiting dozens of women for dinners at the prime minister's residence in Rome.

The fire occurred after she gave a press interview in which she said that, after one of the dinners she had attended, Berlusconi slept with another guest, who was a prostitute.