Italian Prime Minister Silvio Berlusconi is being probed by local magistrates for allegedly pressuring the country’s media watchdog to muzzle pubcaster RAI’s talk shows, which he considers to be hostile to his government.

Prosecutors in the southern city of Trani confirmed today that Berlusconi, who holds sway at the pubcaster and controls RAI rival Mediaset, is under investigation for suspected abuse of office based on wiretaps of phone conversations between him and a member of media regulator Agcom.

In Italy being placed under investigation is not tantamount to being indicted — it implies suspicion, not guilt.

In the tapped conversations — partial transcripts of which were published in the Italian press — Berlusconi allegedly urges Giancarlo Innocenzi, a former Mediaset journalist and current member of the Agcom board, to “shut down” RAI’s “Annozero,” hosted by leftist journalist Michele Santoro.

In the wiretap Berlusconi also allegedly rails against another left-leaning talk show, “Ballaro.”

Santoro had been ousted from RAI by a previous Berlusconi government but was reinstated at the pubcaster by judicial ruling. On Tuesday he was being heard by prosecutors in the probe.

An indignant Berlusconi has denied wrongdoing, calling the probe “grotesque,” and said he was “shocked” that his phone had been tapped.

The Berlusconi government banned all primetime political yakkers in the month leading up to the March 27 and 28 regional elections, allegedly because of concerns they would be critical of the regime.

Last week the Italian judiciary overturned the gag order for private broadcasters but it remains in effect on RAI.

Berlusconi’s lawyer Niccolo Ghedini has called the allegations against his client “completely unfounded” adding that “it was not surprising they should surface less than one month before regional elections.”