Brian Stack, the chief prison officer at Portlaoise Jail was murdered 32 years ago.  

The Garda National Bureau of Criminal Investigation is understood to have identified two men as part of an IRA gang they suspect planned Brian’s assassination.  

The IRA took responsibility for the killing in 2013.

It has emerged that one of the IRA men is suspected of abusing a 12 year old girl, and was moved to Paris.

Brian’s son Austin Stack told his story to Mairia Cahill in the Sunday Independent.

Mr Stack spoke to Jonathan Healy today and detailed his campaign to try to find his father's killer.

He stated: "I got confirmation only last week that one of the individuals in particular, the individual who would have organised my father's murder, that he had been an abuser and the IRA had actually asked him to leave Northern Ireland."

"This guy was a very high profile member of the IRA. 

"He was extremely close to a very leading member of the IRA at the time which may have been why he was spared. But this individual, who was a leading member of the IRA at the time, is a very senior member of Sinn Féin."

Mr Stack then detailed about how he approached Gerry Adams for help to find his father's killer and how he met the IRA subsequently.

"Bear in mind that Brian Stanley, the Sinn Féin TD in Portlaoise up to the end of March was saying that it was his belief that the IRA didn't kill my father. In April 2013 Gerry Adams was denying all knowledge of the murder of my father.

"We come forward a couple of months and all of a sudden, they're admitting that they did it."

He continued: "If Gerry Adams was able to get information for me by going to his IRA sources, surely he's able to get the same information in relation to sex abusers that the IRA have exiled from Ireland.

"Sinn Féin know where these people are.

"If Gerry Adams or other leadership figures in the IRA wanted to get information to help people and to protect children, this is about protecting children... they have to got to do something about this. These are elected public representatives we're talking about here."

He finished by stating: "I am not a bitter man, I would be thankful and I always am to the IRA for meeting us and Gerry Adams for organising it.

"As a father and an ordinary decent human being, I cannot stand by and allow people who know where sex abusers are, who know where people who are a threat to children are, I cannot allow that to go by.

"Go to the IRA, talk to people."

You can listen back to his interview here: