The controversy over the murder of Brian Stack and its aftermath have dominated headlines this week.

It has led to extraordinary scenes in the Dáil and a series of tense exchanges in the media.

What exactly is the controversy about?

Brian Stack

Brian Stack was the chief prison officer at Portlaoise Prison in the early 1980s. 

He was shot on March 25th, 1983. This attack left him paralysed & brain-damaged, and he died 18 months later.

The IRA did not acknowledge responsibility for the attack until 2013.

In a statement to the Stack family released in August of that year, the organisation said: "In Portlaoise a brutal prison regime saw prisoners and their families suffer greatly. This is the context in which IRA volunteers shot your father.

"This action was not authorised by the IRA leadership and for this reason the IRA denied any involvement. Some years later, when the Army Council discovered that its volunteers had shot Prison Officer Brian Stack, the volunteer responsible for the instruction was disciplined.

"Those who carried out the attack were IRA volunteers acting under orders. The IRA was responsible for your father's death. This operation should not have taken place," the statement added.

List of names

An Irish Independent report last month revealed that Gerry Adams had sent an e-mail to the Garda Commissioner this year - naming a number of senior party figures and a former IRA figure in connection with Mr Stack's death.

The Sinn Féin leader claimed to have been given the names by Brian Stack's son, Austin.

However Austin Stack insisted that was not the case.

Austin and Oliver Stack (left to right), sons of Brian Stack. Picture by Niall Carson PA Archive/PA Images

"I can quite categorically state that at no stage did I give names to Gerry Adams," he told Newstalk Breakfast. "He says that I gave him the names - that is not correct."

Mr Stack has also detailed a meeting between the Stack family and a senior IRA figure. Deputy Adams was also in attendance.

Deputy Adams, meanwhile, said in a statement from Cuba: “I responded extensively to this issue when it was raised during the election campaign. In the course of our conversations I was given a number of names by Austin Stack which he told me he had been given by journalistic and Garda sources.

“Austin asked me to ask those named if they would meet with him. I did this with those I could contact. They declined to meet at that time. I told Austin Stack this. I passed the names on to the Garda Commissioner while making clear that I have no information on the death of Brian Stack."

Political reaction

The claims and counter-claims gained major political traction in the Dáil when both Taoiseach Enda Kenny and Fianna Fáil leader Michéal Martin brought up the matter in the chamber after Gerry Adams had returned to the country.

"I think Deputy Gerry Adams knows more about this than certainly I do," Mr Kenny said on Tuesday. "And while this investigation is going on into a murder, perhaps Deputy Adams might - in the privilege of this House - make a statement and clear it up for everybody".

The Sinn Féin leader agreed to make a statement, which he delivered on Wednesday evening.

During his statement - which can be read in full here - Deputy Adams argued: "I emailed the Garda Commissioner the names that Austin Stack had given me and which he said had come from Garda and journalistic sources. I made it clear to the Garda Commissioner that I have no information on the death of Brian Stack. The email was only sent after I had spoken to three of the four.

"My generation of republican activists who lived through and survived the war have a responsibility to try and bring the families of victims of the war, irrespective of who was responsible, to a better place. That is what I have tried to do with my engagement in 2013 with the Stack Family."

He also insisted that he had never described those named in the email as suspects, and also denied a number of allegations - including the Taoiseach's claim that Deputy Adams himself had driven the Stack family to the meeting with an IRA figure in a 'blacked out van'.

Tense Dáil scenes

Alan Farrell. Image: RollingNews.ie

There was more drama to come in the Dáil chamber on Wednesday night following the statement from Gerry Adams.

Fine Gael Deputy Alan Farrell raised what he called a point of order - and under privilege put the names of two sitting Sinn Féin TDs in the public domain.

He requested that "Deputies Ellis and Ferris be given the opportunity to address this House" in connection with the Stack case.

One of those named, Dessie Ellis, says he could not have been involved.

"I was actually in jail for the period in Portlaoise, and before that in America. So you should check your facts", he said.

Deputy Martin Ferris said that in 2013 he met gardaí at their request regarding the killing, stressing that he co-operated and had nothing to answer for.

Deputy Farrell, meanwhile, yesterday admitted he had breached Dáil standing orders - but insisted the incident was not a stunt.

Press conference

Austin Stack (left), son of Brian Stack, a prison officer murdered in 1983, confronts Sinn Fein leader Gerry Adams (right) during a Sinn Fein press conference at the Davenport Hotel in Dublin. Picture by Brian Lawless PA Wire/PA Images

The tensions continued during a press conference held by the Sinn Féin leader yesterday.

Interrupting the press conference at a hotel in Dublin, Austin Stack said: "Gerry Adams, you have information that is crucial to the investigation of my father's murder. Gerry Adams, you took myself and my brother Oliver in a blacked-out van to meet with a senior IRA figure - a man you say you trusted.

"Gerry Adams, I want you to give that information to An Garda Síochana. I am not interested in hearing any more of your lies and untruths [...] I want you to take the information that you have and bring it to An Garda Síochana, Gerry Adams, because you as a public representative are an absolute disgrace if you don't."

Deputy Adams 'rejected absolutely' any allegations that he had told lies or untruths.

Speaking to Newstalk Breakfast yesterday morning, Michéal Martin had accused Gerry Adams of using the peace process as an excuse not to tell the truth about the murder of Brian Stack.

Yesterday evening, Enda Kenny said during an interview on RTÉ that Gerry Adams should name the driver of the van that brought Austin and Oliver Stack to the meeting with the IRA.

He also described Mr Adams' statement in the Dáil as "incomplete".

Mr Adams responded in a statement by saying that if the Taoiseach is serious about assisting victims, he should focus his energy on establishing a proper truth recovery process. 

“Why has the Taoiseach waited until now to make this call when a process was agreed between me and Austin and Oliver Stack that culminated in a meeting between the Stack brothers and a former IRA leader in 2013?" he asked.