"No Stone Unturned," a new documentary about the notorious 1984 Loughinisland massacre that was shown for the first time at the New York Film Festival on Saturday, has named the chief suspects for the first time.

They are named as Ronald Hawthorn, Alan Taylor, and Gorman McMullen.

The Loughinisland massacre took place on June 18, 1994, in the small village of Loughinisland, Co Down, Northern Ireland. Members of the Ulster Volunteer Force (UVF), a loyalist paramilitary group, burst into a pub with assault rifles and fired on the customer's, killing six civilians and wounding five. The pub was targeted because it was frequented mainly by Catholics and was crowded with people watching the Republic of Ireland play in the World Cup.

The documentary "No Stone Unturned," by the Oscar-winning director Alex Gibney, also states that one and perhaps two of the suspects were also police informers.

Read More: Explosive film on a Northern Ireland massacre to debut at New York Film Festival

In another shocking charge, the documentary alleges that members of the police had known about the intended shootings but did nothing to stop them, even warning one suspect before he knew the massacre was on to expect arrest and questioning the following day. The job was almost called off because the car they had purchased had mechanical problems.

The documentary also alleges that it was the wife of one of the suspects who tipped off police, a leading Irish journalist and a politician to the identity of the killers. Her motives are unknown, and she is still married to the suspect. One of the suspects was brought in for interrogation but a former Royal Ulster Constabulary officer stated to the program most of the time was spent attempting to get him to organize a hit job on a leading Republican.

One of the suspects lives close to families who lost loved ones in the slayings, and he now runs an extermination business. No photograph or video of him has ever been seen but the documentary succeeded in filming footage of him.

The gun used in the killing was a Czech-made assault rifle called VZ585, part of a shipment to Loyalist groups. 200 assault rifles were landed and were used in 70 killings. Police were tipped off about the consignment but lost track of the ship, they said. Noel Little, father of Democratic Unionist politician Emily Little Pengelly was jailed in France for helping secure the weaponry.

The car used in the killings was sold for scrap, the interrogation notes on many suspects were destroyed and key evidence mysteriously disappeared. Several police officers are implicated in the cover-up by the documentary.

Several members of the Loughinisland families who lost loved ones were present at the Walter Reade Theater for the first showing was their lawyer Niall Murphy.

Director Gibney paid tribute to their courage and persistence in a Question and Answer period after the screening.

Releasing his 2016 report of the massacre, Northern Ireland Police Ombudsman Dr. Michael Maguire said he had no hesitation in determining collusion between police and security services and loyalist paramilitaries happened at the highest levels. The new documentary takes those charges much further and identifies the chief suspects as well as the police who worked the case but who many suspect of a cover-up.