A prosecutor who requested a six-year sentence for Italy's former Prime Minister Silvio Berlusconi has been sent threats including a letter with two bullets, her office says, according to BBC News.

Ilda Boccassini also asked that Berlusconi be banned for life from public office for allegedly paying for sex with a 17-year-old dancer.

Both the dancer, Karima El-Mahroug, and Berlusconi have denied the allegations. A verdict is expected on June 24.

"In the last few weeks there has been a crescendo of anonymous letters containing serious threats against Boccassini, including one yesterday containing two bullets," Milan prosecutor Edmondo Bruti Liberati said in a statement.

He added that the prosecutors' office would continue to fulfill its duties with "unchanged serenity".

In the trial, the prosecution in Milan have alleged that women were invited to Berlusconi's private residence for so-called "bunga-bunga" party evenings as part of a prostitution system set up for his personal sexual satisfaction.

Paying for sex with a 17-year-old is an offence under Italian law.

Berlusconi is also charged with abusing his power of office after calling a police station to press for the release of Mahroug when she was arrested in Milan in a separate petty theft case.

He has acknowledged the phone call but says it was made as a favor to former Egyptian President Hosni Mubarak, whose granddaughter he believed Mahroug to be.

The 76-year-old already faces a four-year prison sentence and five-year ban from public office for a fraud conviction, which he is expected to appeal against in Italy's highest court, the Court of Cassation.

Earlier this month Italian prosecutors requested a new corruption trial against Berlusconi, saying he had allegedly bribed a left-wing senator to defect to his right-wing People of Freedom party (PDL) in 2006.

Berlusconi claims he is the victim of a campaign by left-wing magistrates.