ROME Jan. 14, 2011 -- Italian Prime Minister Silvio Berlusconi has come under investigation for allegedly having sex with a 17-year-old prostitute and then covering up his involvement.
Prosecutors have requested the 74-year-old Berlusoni appear before them later this month and said they would ask for a fast track trial.
Berlusconi's lawyer called the allegations "absurd and groundless."
The flamboyant prime minister, a billionaire businessman who has managed to evade previous accusations of sexual and financial impropriety, is accused of paying teen prostitute Karima el-Mahroug, better known as Ruby the Heart Stealer, for sex parties he held last year at his Milan villa.
The scandal, considered tawdry even by Italian standards, has further weakened the prime minister, who lost his latest battle to protect himself from prosecution Thursday when the Italian high court struck down a law that had shielded him from trial in three unrelated corruption cases.
Berlusconi is no stranger from the front pages of the world's tabloids. In 2009 his wife called him "shameless" and filed for divorce after a series of allegations that he had sex with prostitutes and had attended the birthday party of an 18-year-old model.
Berlusconi's relationship with Ruby became public last year, when it emerged that the prime minister had intervened when police arrested her for theft. Berlusconi is accused of calling the Milanese police in March and sending Nicole Minetti, a former showgirl who represents Berlusconi's party in parliament, to intervene. Minetti is also under investigation. Berlusconi reportedly told the police Ruby was the niece of Egyptian president Hosni Mubarak.
The investigation is focused in part on whether Berlusconi intervened in order to keep secret the fact that he had been Ruby's client and that she was 17.
Berlusconi's attorneys, Nicolo Ghedini and Piero Longo, called the probe a "very serious interference in the prime minister's private life that has no precedent in the country's judicial history."
They called the case media-driven, and said the allegations "have already been refuted by all witnesses and people directly involved."
Ruby told Milanese prosecutors last year that the prime minister had showered her with over $1,300 worth of cash and jewelry and invited her to two sex parties, including a Arabian-style orgy called "bunga bunga," that included 20 women.
The young Moroccan teenager, now 18, said Berlusconi claimed to have learned about bunga-bunga parties from Libyan dictator Muammar Khaddafi. At the party, she said, Berlusconi was naked and surrounded by 20 nude women, according to Italian newspaper La Repubblica.
"Silvio told me that he'd copied that formula from Muammar Khaddafi," she told prosecutors according to La Repubblica. "It's a ritual of [Kaddafi's] African harem."
In newspaper interviews Ruby has said she lied about her age and did not have sex with Berlusconi.
If Berlusconi is convicted of paying a minor for sex, he can face up to three years in prison and a fine of no less than 5,164 euros. For the charge of covering up his involvement, he could face up to 12 years.
In Italy, the age of consent is 14. However, paying for sex with a minor between the ages of 14 and 17 carries penalties.
The Associated Press contributed to this report.