Italian Prime Minister Silvio Berlusconi faced fresh pressure on Saturday over allegations that he had partied with a young teenage girl, as the leader of the opposition called on him to resign over the affair.

“Berlusconi can’t stay a minute longer in a public role that he has betrayed in an indecent manner,” said Pier Luigi Bersani, leader of the Democratic Party (PD) following the latest allegations.

According to Italian media reports, when police arrested a young Moroccan named Ruby for theft, she claimed she had been to a number of parties in Mr Berlusconi’s villa in Arcore, near Milan.

The reports said Ruby, an aspiring model, had tried to resist arrest by telling police she knew the 74-year-old Prime Minister from parties she had attended at Arcore.

Mr Berlusconi’s lawyers strongly deny any suggestion the Prime Minister may have had sexual relations with the girl.

“Italy has a dignity that cannot be jeopardised across the world,” Mr Bersani added. “Italy has problems that must be confronted once and for all in a serious atmosphere.”

Reports about Mr Berlusconi’s private life regularly hit the headlines in Italy. He was implicated in a series of scandals in 2009 that led his wife Veronica Lario to file for divorce.