Italian Prime Minister Silvio Berlusconi may have told a businessman to lie to investigators about paying callgirls to attend parties he hosted, AFP reports, citing the Ansa news agency Tuesday.

The businessman, Gianpaolo Tarantini, is on trial accused of having spent nearly 30,000 euros ($41,000) on recruiting dozens of women for Berlusconi's private parties in 2008 and 2009 in order to win lucrative contracts.

Quoting a decision by a Naples court, Ansa said Berlusconi may be questioned about claims that he asked Tarantini to make false declarations in the callgirl probe.

This could lead to a full investigation against the prime minister, the agency said.

The trial of Tarantini and eight others in Bari, southern Italy, has not directly implicated Berlusconi in anything illegal. The renting of prostitutes is not illegal in Italy and Berlusconi has so far only been a witness in the case.

According to reports, the probe has found that Tarantini paid about 30 young women to spend evenings with Berlusconi at his private residences in Rome or Arcore, near Milan, between July 2008 and April 2009.

The businessman allegedly paid those who spend the night in the prime minister's bed 1,000 euros, and newspapers quoted telephone taps as indicating that Berlusconi also gave some of them 100 euro bills in envelopes.

The 74-year-old premier already faces a string of legal cases, including one in which he is accused of having paid for sex with a nightclub dancer Karima El Mahroug, nicknamed "Ruby the Heart Stealer", when she was a minor.

He is also accused of having abused his power to spring her from police custody when she was arrested on suspicion of theft.

The next hearing in that case is set for October 3.

Tarantini has been in custody since September 1 accused of extorting 850,000 euros ($1.2 million) from Berlusconi to lie to prosecutors about the parties.

The court in that case this month asked to hear from Berlusconi as the "victim" in the alleged blackmail case.

But the billionaire tycoon has said he gave the money as a gift to help a friend in need, and has refused to appear before the Naples judges.

According to Ansa, the Naples court has ruled to free Tarantini from custody.

Berlusconi also faces trials for fraud, bribery, and revealing court secrets.

On Monday, Cardinal Angelo Bagnasco, head of the conference of Italian bishops, condemned "behaviour that, if proven, is difficult to reconcile with institutional decorum".

He did not name Berlusconi or any other Italian politician.

But he added: "Anyone who chooses to be active in politics must be conscious of a measure of sobriety, discipline and of the honour that (politics) entails."

Berlusconi, a billionaire tycoon, has a long history of legal entanglements dating back to when he first entered politics in the early 1990s.

So far, the cases against him have either run out of time or ended in his being exonerated.

But the constant publicity over his private life and the endless legal battles him have hit his popularity hard: he is at an all-time low in the opinion polls.