Silvio Berlusconi is at the centre of further sordid revelations about his private life after the Italian leader was caught boasting of having sex with eight women in one night.

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Mr Berlusconi was recorded gloating about the encounters, and lamenting that he could not manage another three women that night. The conversations were wire-tapped as part of an investigation into an alleged prostitution ring surrounding the prime minister.

The conversations would appear to contradict Mr Berlusconi’s persistent claim that he had never paid for sex.

The revelations came as opposition leaders demanded an inquiry into claims that the Italian government aircraft flew a bevy of young escorts to Mr Berlusconi's private parties.

Italian newspapers yesterday charted transcripts of phone conversations of an imprisoned businessman Gianpaolo Tarantini, who is under investigation for arranging for prostitutes to frequent parties at Mr Berlusconi’s private homes.

Mr Berlusconi, who turns 75 later this month and is grappling with sliding approval ratings, faced fresh political headwind from riots in Venice yesterday.

Venice police clashed with protesters marching against anti-immigration party Northern League, one of Mr Berlusconi’s key allies.

Some 800 protesters clashed with police on Saturday during an anti-Northern League march in Venice.

Clashes began when demonstrators tried to breach a police blockade of the city centre, throwing firecrackers and smoke bombs and striking out with long poles. Eleven people were injured, including two policemen and Venice councilman Beppe Caccia, Italian media reported.

The rift with the Northern League, which has long called for independence of Italy's industrialised northern regions that they claim subsidise the country's poor south, continues to accelerate the country's dwindling support for the Berlusconi administration.