Italian magistrates are investigating Prime Minister Silvio Berlusconi over allegations he put pressure on state broadcaster RAI to suppress a programme critical of the government, judicial sources said on Tuesday.
The investigation centres on AnnoZero, a political talk show hosted by Michele Santoro, a veteran Italian journalist and strong Berlusconi critic, which the prime minister is alleged to have tried to get removed from the airwaves in 2009.
It also targets former RAI director general Mauro Masi and the former head of communications authority AGCOM, Giancarlo Innocenzi.
Berlusconi, owner of Italy's largest private broadcaster Mediaset , is accused of abusing the powers of his office as prime minister by putting pressure on Masi and Innocenzi to have AnnoZero taken off the air.
The show ended its run after Santoro left RAI this year.
Berlusconi is already facing three trials for fraud or corruption, in addition to the "Rubygate" case where he is charged with paying for sex with an underage prostitute. He denies all charges against him.
Critics of Berlusconi have long accused the media tycoon of having excessive sway over Italian television through his control of Mediaset and indirect influence over RAI, whose board members are appointed by the government.
Alleged media bias towards Berlusconi's government is a frequent subject of controversy in Italy, and the communications regulator last year accused three major news programmes of biased reporting.
Rome prosecutors are also probing Berlusconi for alleged abuse of office after he appeared, in television interviews, to be rallying supporters for local elections earlier this year.