"There is no doubt that Silvio Berlusconi is guilty of the crimes he is accused of," prosecutor Ilda Boccassini told the Milan courtroom at the close of a two-year trial that could rock the country's newly formed grand coalition government.

"He had sex with her and he knew she was a minor," said the prosecutor, who has locked horns repeatedly with Berlusconi in past legal cases.

"We request a sentence of six years in prison" for the senator, she said, adding: "We ask for a perpetual ban from holding public office."

The trial relates to crimes allegedly committed in 2010 when Berlusconi, 76, was prime minister for the third time in his career and revolves around what prosecutors say were raunchy "bunga bunga" parties at his luxury residence outside Milan.

"The women invited to the then prime minister's private residence were part of a prostitution system set up for the personal sexual satisfaction of the defendant," Boccassini said.

Berlusconi, who was not present at the hearing, hit back in a statement saying the case was built on "theories, conjecture, distortions and falsehoods inspired by prejudice and hatred".

Berlusconi's defence lawyers will now have a chance to present their final arguments on June 3rd.

The verdict could come at the hearing after that, which has been scheduled for June 24th.

Both Berlusconi and the woman involved have denied ever having sex.

Berlusconi is accused of paying for sex on several occasions with Moroccan-born Karima El-Mahroug, a then 17-year-old exotic dancer nicknamed "Ruby the Heart Stealer" who was spotted by one of his associates at a beauty contest in Sicily in 2009.

Boccassini said El-Mahroug quickly became the premier's "favourite" and had not admitted the relationship with him only because she had received as much as 4.5 million euros ($5.8 million) from the flamboyant billionaire tycoon.

Boccassini said El-Mahroug had followed a "negative Italian dream" based on money and accused her of "Oriental cunning" — a remark that was quickly criticized by observers as racist.

It is also alleged that Berlusconi called a police station to pressure for El-Mahroug's release from custody when she was arrested for petty theft – an abuse of his office of prime minister.

According to prosecutors, he did so because he feared she could reveal their liaison.

His defence claims he believed El-Mahroug was the niece of former Egyptian president Hosni Mubarak and wanted to avoid a diplomatic incident.

A programme on Sunday on a television channel he owns included interviews with Berlusconi and El-Mahroug in which the two spoke of "perfectly normal" soirees that had been wrongly portrayed. 

Three of Berlusconi's friends — a show-business agent, a former network anchor and a former regional assemblywoman — are on trial on pimping charges in a separate trial linked to the case.

El-Mahroug, who has not spoken at Berlusconi's trial, is due to testify at that trial on Saturday.

Berlusconi has only occasionally attended hearings.

The scandal-tainted politician's legal woes are straining relations within Prime Minister Enrico Letta's coalition government in which Berlusconi's People of Freedom party is a crucial partner.

Berlusconi has been under investigation or on trial ever since entering politics in the 1990s after a career in construction and media.

He says the trial is only the latest example of a 20-year "judicial persecution" by left-wing prosecutors who are out to get him.

A Milan court this month upheld his conviction on tax fraud charges related to his business interests, confirming the punishment of a year in prison and a five-year ban from public office which is frozen pending a second appeal.

Prosecutors in Naples have also requested a trial against Berlusconi on allegations that he bribed a left-wing senator with three million euros to join his party and topple a past centre-left cabinet.

Even if convicted after exhausting two rounds of appeals, Berlusconi is unlikely ever to see the inside of a prison cell because of relatively lenient sentencing guidelines for over-70s.