The Italian prime minister is accused of paying an underage prostitute and abusing his powers as leader to cover up the sordid affair.
The 74-year-old has denied the sex allegations, but the affair is threatening to bring down his government.
Prosecutors claim they have intercepts of telephone conversations which incriminate the PM.
Court documents allege he gave several thousand euros to a girl calledKarima El-Maroug – known as Ruby – when she was 17.