MILAN - Italian Prime Minister Silvio Berlusconi's legal marathon resumes this week with a tax fraud hearing on Monday that will be followed two days later by the long-awaited "Rubygate" trial. The Ruby case, in which the 74 year-old premier is accused of paying for sex with a teenaged nightclub dancer when she was below the legal age limit of 18, has gripped media attention like few others in recent years. But it is only one element in a web of legal problems for Berlusconi, one of Italy's richest entrepreneurs as well as its prime minister and dominant political figure. Over the coming weeks, he faces a series of related trials linked to allegations of fraud, embezzlement and corruption over dealing in television rights by parts of his Mediaset broadcasting empire. Some of the cases already have opened and Monday's hearing on fraud charges linked to Mediatrade, a unit of Mediaset that deals in broadcast rights, is expected to provide few fireworks, as the prime minister will not be present. The case centers on accusations that Berlusconi's companies deliberately overpaid for TV and film rights, allowing the difference to be skimmed off by offshore companies run by frontmen and put into illegal slush funds. Berlusconi, who appeared at a first hearing last week but who will be in Tunisia for talks on the migrant crisis in southern Italy, denies any wrongdoing and says he has been targeted by politically motivated leftwing magistrates. His opinion poll ratings have suffered but he is in little danger of being forced from office before a verdict which may take years or which may never come. He has faced at least a dozen trials over the years and has always been cleared or seen the statute of limitations clock run down on the charges he has faced.