Police have been ordered to return vast amounts of documents seized from two journalists arrested for airing confidential material in a documentary.
Lord Chief Justice of Northern Ireland Sir Declan Morgan said the granting of a search warrant for their homes and offices was “inappropriate”.
Trevor Birney and fellow film-maker Barry McCaffrey acted in a perfectly proper manner to protect their sources and not hand over the information voluntarily, the country’s top judge said.
The pair lauded the decision by three Belfast judges as a victory for press freedom.
They were detained last year over the alleged theft of a police watchdog document that appeared in their film No Stone Unturned, which is about the murders of six men in Loughinisland, Co Down, in 1994.
Mr Birney said: “What has happened today has been a correction of an injustice and a correction of an attack on the freedom of the press not only in Belfast but on the island of Ireland and throughout the UK.
“This court has stood over the press, it has supported the press and upheld the importance of a free press in a liberal society.”
The men remain under police investigation and are on bail.
The award-winning reporters mounted the Belfast High Court challenge against police, accusing them of unlawfully seizing millions of journalistic documents and digital files when they raided their homes and offices in the city last August.
Sir Declan said: “The material that was before the judge and the material which was subsequently demonstrated to us does not indicate that the journalists acted in anything other than a perfectly proper manner with a view to protecting their sources in a lawful way.”
The judge said the suspected theft did not provide any basis for the execution of the warrant.
The 2017 film broke new ground by naming suspects it said were involved in the Ulster Volunteer Force (UVF) killings of six Catholic men gathered in a village pub watching the Republic of Ireland play a World Cup football match on TV.
Mr Birney and Mr McCaffrey took the judicial review against the execution of the police search warrant.
Sir Declan said the two men were doing what the National Union of Journalists (NUJ) requires them to do in protecting the identity of their sources.
A barrister for Mr Birney, Barry Macdonald QC, told the Court of Appeal that police had agreed to return the journalistic research material, more discussion is due surrounding the logistics of doing so.
Police Service of Northern Ireland (PSNI) barrister Peter Coll did not rule out appealing against the decision.
Mr Macdonald said police had agreed not to further examine the seized material or the information contained in it.
The journalists agreed to keep the documents in case they were the subject of a court order requiring its production, within a defined period of time.
Outside court, Mr Birney and Mr McCaffery celebrated the ruling with supporters, including former Brexit secretary David Davis.
No-one has been convicted of the Loughinisland murders.
In a 2016 report, Ombudsman Dr Michael Maguire concluded the security forces colluded with the UVF killers.
NUJ assistant general secretary Seamus Dooley said: “In a democratic society, trust in the police is vital. That trust was shattered by the actions of the PSNI and Durham Constabulary.
“Today’s ruling by the High Court sets the standard for future behaviour and I hope that the incoming chief constable pays attention to the judgment.”
Police are investigating how information contained in a Police Ombudsman for Northern Ireland document appeared in No Stone Unturned.
PSNI Chief Constable George Hamilton, citing a potential conflict of interest, asked Durham Constabulary to take on the probe in the wake of the film’s release.
Chief Constable Mike Barton, of Durham Constabulary, said: “We followed due process when applying for the search warrants. A detailed application was presented to a County Court judge who granted the warrants.
“We respect the outcome of today’s hearing and the judge’s decision, and we will consider its implications.”
Mr Barton will accompany Mr Hamilton at the next meeting of the Northern Ireland Policing Board next Thursday.