A journalist would be targeted for immediate assassination if she surrenders information about the Real IRA to police, a court has heard.

A judge will decide next week whether Belfast journalist Suzanne Breen should be forced to reveal sources and hand over confidential material to police.

Ms Breen, who is the Northern Editor of the Sunday Tribune, was the journalist who received the Real IRA's claim of responsibility for the murder of two British soldiers at Massereene Barracks in March.

During a hearing at Belfast Recorders Court yesterday, Ms Breen said her life would be in immediate danger if she was forced to comply with the PSNI’s request, and that her reputation as an investigative journalist would be ruined.

Ms Breen was contacted by police to hand over confidential material following the publication of articles which included an interview with a representative of the RIRA following the murders.

However, upon consulting with her editor, Noreen Hegarty, she refused, citing the National Union of Journalist’s code of ethics to protect all confidential sources as her reason.

The police have said they need this information as part of the murder inquiry and are using anti-terror laws to try to seize phones, computers and notebooks.

During her evidence yesterday, Ms Breen told the court that she had been warned by third parties that she would be seen as a legitimate target by the RIRA if she was forced to reveal her sources.

“It has been reinforced through third parties and I have now been told that my life would be in danger if I co-operate with the PSNI. This is not a theoretical threat, it is real,” she said. “The Real IRA would treat me in the same way as they treated the pizza delivery men. They would treat me as a legitimate target. My life would be in immediate and absolute danger.”

Ms Breen also argued that if she was forced to comply it would ruin her credibility as a journalist and that of the Sunday Tribune.

Her argument was backed by a number of well-respected British and Irish journalists including Liam Clarke, formerly of the Sunday Times, who testified that he himself had received death threats from paramilitaries.

Others to back her stance were Alex Thomson of Channel 4 News, former Mirror editor Roy Greenslade, now Professor of Journalism at London City University, and BBC Panorama reporter John Ware.

Mr Ware — who described Ms Breen as a model of integrity, accuracy and fairness who had made an enormous contribution to understanding the conflict in Northern Ireland — said it was an “iron clad” rule.

He stressed that paramilitaries who call a named journalist do not expect any details to be given to the authorities other than to save lives or protect property.

“There is no doubt about it, there will be a chill which goes from this court to every part of the administration of this country,” he said.

In closing submissions, Tony McGleenan, counsel for the Chief Constable, argued that while the material may cause her professional concern it would be of evidential value to the police investigation.

Dr McGleenan argued the NUJ code carried no legal force and claimed there was no current and immediate threat to life. Any future risk would place an obligation on the Chief Constable and other agencies to provide protection, he accepted.

But Arthur Harvey QC, for Ms Breen, argued Ms Breen was told through other reliable sources that if she did reveal this information she would be killed.