* Judge says court cannot restrict reporting of parliament
* O'Brien is one of Ireland's most powerful press barons
* O'Brien says accusations of sweetheart loans contain falsehoods (Recasts after court's decision, adds O'Brien comments)
By Padraic Halpin
DUBLIN, June 2 (Reuters) - Ireland's state broadcaster aired a lawmaker's speech accusing a billionaire of obtaining sweetheart bank loans, after a court ruled on Tuesday that the right to report on parliament trumped a court order to muzzle potentially libellous allegations.
Billionaire press baron Denis O'Brien says accusations of financial wrongdoing against him contain falsehoods. He obtained a court order in May preventing state broadcaster RTE from running a report about his business affairs.
But last week lawmaker Catherine Murphy repeated the allegations in parliament, a venue that normally provides "absolute privilege" - the right of the media to report what is said free of any restriction.
RTE appealed on Tuesday for the right to report Murphy's speech, and won the backing of Judge Donald Binchy.
"It's clear to me that the court can't make restrictions on the fair reporting of utterances in Dáil Éireann," Binchy told a packed court room, referring to parliament's lower house.
Kevin Bakhurst, Managing Director for RTE News and Current Affairs told reporters that the clarity provided by the judge was "an incredibly important message to send out to members of the Dail and members of the press in Ireland."
Murphy told the Newstalk radio station: "I welcome the clarification, it's very important. It vindicates the democratic function of the Oireachtas (houses of parliament)."
O'Brien is one of Ireland's most powerful press barons, owner of its biggest circulation newspaper, the Irish Independent, as well as four other national newspapers, 13 regional newspapers and two major national radio stations.
In Murphy's speech, she said O'Brien had paid a below-market interest rate for loans from the state-owned Irish Banking Resolution Corporation (IBRC), the wind-down vehicle for a bank that collapsed during the 2008 financial crisis.
Writing in the Irish Times ahead of the hearing on Tuesday, O'Brien said Murphy repeatedly made erroneous and untruthful statements about his banking relationship.
"I agree that Dáil (parliament) privilege is an important component of our democracy; however, there is a parallel duty of care on the TDs (members of parliament) and Senators to use this privilege with integrity," O'Brien wrote.
His spokesman has declined to explain what parts of Murphy's speech were untrue, arguing that to do so would violate the court order on reporting his affairs.
Murphy's five-minute speech was delivered to a near-empty parliament chamber, but dominated the media since, with the court-imposed blackout becoming the story in newspapers that did not discuss the speech's contents.
The hashtag #obrienvmedia was the top trending issue on Twitter in Ireland on Tuesday.
As in many countries that inherited the British legal system, Ireland's courts have broad powers to issue injunctions preventing publication of news stories that may be libellous. Often details of the injunctions themselves must be kept secret, since publishing them would reveal the story itself. (Editing by Carmel Crimmins, Guy Faulconbridge and Peter Graff)