Two journalists arrested for airing confidential material in a documentary acted in a perfectly proper manner to protect their sources, Northern Ireland's top judge said.

Trevor Birney and fellow film-maker Barry McCaffrey were detained last year over the alleged theft of a police watchdog document that appeared in their film No Stone Unturned.

The documentary is about the murders of six men in Loughinisland, Co Down, in 1994.

Lord Chief Justice of Northern Ireland Declan Morgan said the granting of a search warrant for their homes and offices was "inappropriate".

The men remain under police investigation and are on bail.

Justice Morgan 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."

He added: "We consider that in any event in the light of the legal authorities that the execution or granting of the search warrant was inappropriate."

He said they were doing what the National Union of Journalists requires them to do with regard to protecting the identity of their sources.

He added the material should be returned to the journalists but they could consider giving an undertaking to retain it for a period, in case it was required to be produced.

The award-winning reporters mounted a 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 Belfast last August.

At the conclusion of the hearing in Belfast High Court on Wednesday, Northern Ireland's Lord Chief Justice, who heard the case alongside two fellow judges, said they were "minded to quash the warrants".

On Wednesday the senior judges held that authorisation for the searches which led to the arrest of Trevor Birney and Barry McCaffrey had been inappropriate.

The case is connected to the murders of six Catholic men at Loughinisland, Co Down in June 1994.

UVF gunmen opened fire in a pub as their victims watched a World Cup football match.

The award-winning investigative journalists were involved in the documentary film 'No Stone Unturned', which examined the RUC's handling of the Loughinisland atrocity.

In August of last year they were detained, questioned and released during an operation undertaken by detectives from Durham Constabulary, supported by PSNI officers.

Judicial review proceedings were brought in a bid to have the warrants declared unlawful.

All of the seized material remains under seal, with police having given an undertaking not to examine any of the documents and computer equipment pending the outcome of the legal action.