BELFAST (Reuters) - Two journalists were arrested on Friday over the suspected theft of documents from Northern Ireland’s police ombudsman that were used in a documentary that alleged police collusion in the 1994 murder of six soccer fans.

The two were later released on bail, police said, and the documentary makers secured a temporary court order to stop police examining documents and material seized in raids on Friday.

The 2017 documentary “No Stone Unturned” named a Protestant paramilitary gunman it said police believed shot six fans in one of the most notorious episodes of Northern Ireland’s ‘Troubles’.

It also detailed alleged police collusion, which a 2016 report by the Northern Ireland police ombudsman said was a significant feature in the killings. No one has been prosecuted for the killings.

The arrests, made in a joint operation between police from Northern Ireland and the northern British region of Durham, relate to the suspected theft of materials held by the office of the Police Ombudsman of Northern Ireland, police said in a statement.

“The inquiry centers on the theft of sensitive material, which was used in a documentary film re-examining the 1994 murders,” the statement said, adding that the theft “potentially puts lives at risk.”

A Durham police spokesman later said the two had been released on bail pending further enquiries, which he said were likely to continue for a number of months.

The producer of the documentary, Alex Gibney, said on Twitter that the pair had been arrested “for doing good, hard-hitting journalism.”

“The film exposed the failure of police to properly investigate Loughinisland Massacre and bring suspected killers to account,” Gibney said. “Police reaction? Re-open murder investigation? No. Arrest the truth tellers.”

On June 18, 1994, Protestant paramilitary gunmen entered the Heights Bar in the village of Loughinisland and opened fire indiscriminately on customers watching Ireland play Italy in a televised World Cup match, Six were killed, including 87-year-old Barney Greene, one of the oldest victims in the ‘Troubles’.

Among the failings identified in the 2016 Police Ombudsman report was that police informants at the most senior level within armed Loyalist groups were involved in the importation of arms used in at least 70 murders and attempted murders, including the Loughinisland killings.

Over 3,600 people died during the 30-year armed conflict between Catholic Irish nationalists seeking a united Ireland and their Protestant rivals who want to keep Northern Ireland British.