Naples, Sep 1 (IANS/AKI): An Italian businessman who has been accused of supplying Silvio Berlusconi with prostitutes for sex parties was arrested Thursday on suspicion of extorting money from Italy's billionaire prime minister.

Giampaolo Tarantini, a 36-year-old a businessman from the southern Puglia region, in 2008 was the target of a probe into abetting prostitution. He has admitted to corruption and furnishing Berlusconi's parties on the island of Sardinia and Rome with more than 30 women - many of them prostitutes.

He was arrested in Rome together with his wife Angela Devenuto, 34, and transferred to Naples where the couple was detained in separate prisons.

Investigators from Naples have gathered "evidence of repeated dation by Berlusconi and in favour of the Tarantini spouses of sums of cash other than benefits of a financial character", a statement from Italian investigators said Thursday.

Investigators say they listened in on phone conversations between Tarantini, Devenuto and another suspect, which contain evidence that Berlusconi paid 500,000 euros and 20,000 euros in monthly payments. The conversations shed light on an agreement that Berlusconi would pay Tarantini to lie to investigators, saying he was unaware that many female guests at erotic parties were paid for for their attendance.

In fact, Tarantini has always backed Berlusconi's claim that the 75-year-old premiere did not know that women were paid to attend his parties.

Investigators say the third target in the phone taps - ex-director and editor of Socialist newspaper Avanti! Valter Lavitola - had the job of passing the 500,000 euro payment to Tarantini but kept 400,000 for himself. Police say he is a fugitive.

Berlusconi faces four criminal trials in Milan, including for corruption and underage prostitution. He says he has broken no laws.