Magistrates investigating an alleged prostitution ring in Italy have published wiretaps in which Silvio Berlusconi boasts of spending the night with eight women and complains that meetings with Gordon Brown and the Pope are interfering with his partying.

The wiretaps were released at the conclusion of an investigation into entrepreneur Gianpaolo Tarantini, who is accused of paying women to sleep with Berlusconi, 74, at his homes in 2008 and 2009. The Italian prime minister is not under investigation, although the wiretaps throw doubt on Berlusconi's claims that he has never paid for sex.

"They are all well provided for," Berlusconi tells Tarantini of the girls passing through his Rome residence in one of the thousands of recorded conversations released, which filled Italian newspapers on Saturday.

In another conversation, a woman named Vanessa Di Meglio sends a text from Berlusconi's residence to Tarantini at 5.52am asking "Who pays? Do we ask him or you?"

Tarantini first made the headlines through the revelations of prostitute Patrizia D'Addario, who claimed Tarantini recruited her to have sex with Berlusconi. A second scandal has erupted over Berlusconi's parties at his villa near Milan, with the prime minister on trial accused of paying underage Moroccan dancer Karima El Mahroug for sex.

The newly published wiretaps give startling insight into Berlusconi's sexual appetites. "Last night I had a queue outside the door of the bedroom… There were 11 … I only did eight because I could not do it anymore," Berlusconi told Tarantini in 2009. "Listen, all the beds are full here … this lot won't go home, even at gunpoint."

Berlusconi, who boasted to one TV showgirl that he was only "prime minister in my spare time", told Tarantini in September 2008 that he needed to reduce the flow of women since he had a "terrible week" ahead seeing Pope Benedict, Nicolas Sarkozy, Angela Merkel and Gordon Brown. Berlusconi has long insisted that his private parties are informal but elegant affairs, that extend only as far as joke telling and songs, but is revealed on the tapes as putting pressure on Tarantini and his associates to conjure up beautiful female guests.

One associate is heard complaining he will need a caravan to pick up all the girls, while in another conversation Tarantini says to a colleague: "Find a whore, please."

Tarantini, an entrepreneur from Bari who sold prosthetic limbs before meeting Berlusconi in 2008, quickly became a confidant of the prime minister. "Listen Gianpaolo, now we need at most two each," said Berlusconi in one call. "Because now I want that you have yours, otherwise I will always feel I am in your debt. Then we can trade. After all, the pussy needs to go around."

Berlusconi also sought to impress his female guests by inviting senior managers from his cinema production company and from state TV network RAI.

"These are people who can get jobs for whoever they want," he told Tarantini. "Therefore the girls will get the idea that they are in front of men who can decide their destiny."

Tarantini is suspected of procuring women for other top officials, including a magistrate and a manager at state controlled defence group Finmeccanica. In a separate probe, he has also been arrested on suspicion of seeking to blackmail Berlusconi through an intermediary in return for keeping the lid on details of his procurement of women. Berlusconi has claimed the money he paid out, believed to be more than ¤500,000, was merely financial assistance.

In a letter published in the newspaper Il Foglio, Berlusconi hit back at the latest wiretaps, claiming: "My private life is not a crime, my lifestyle may or may not please, it is personal, reserved and irreproachable."

Opposition leaders meanwhile demanded an inquiry into suggestions in the wiretaps that Berlusconi used government aircraft to ferry prostitutes to his parties. "Italy, with its grave problems cannot allow itself an executive which governs in its spare time. The time for words is over, Berlusconi must go to the Italian president and resign," said Davide Zoggia, an official for the opposition Democratic Party.

Already in trouble in the polls after pushing through a painful austerity budget, Berlusconi's political support took another blow over the weekend as his crucial partner Umberto Bossi, head of the Northern League party, warned that the administration would not make it to the end of its mandate in 2013.

Encouraging support, however, came from Russia, where Vladimir Putin said: "They criticise [Berlusconi] because they are jealous."