The son of a man killed by the IRA says his family has been subjected to a “pattern of untruthful deception”.

Portlaoise Prison officer Brian Stack was shot and killed in 1983. Gerry Adams claims he handed over the names of four suspects to the Garda Commissioner in February, after he was given them by Mr Stack’s son Austin.

Mr Stack denies he gave the names and says the Sinn Féin leader’s version of events is riddled with inconsistencies.

“These untruths have gravely hurt me on a personal level and I’m very disappointed in Gerry Adams, as a public representative, that he would behave in such a fashion,” he said.

“In my view, this is compounding the hurt and the pain that my family have felt.”

Yesterday, Mr Adams (pictured) said: “I have to say I’m very disappointed. I went out to help the Stack family [when he met them to help confirm the murder was by the provisional IRA]. They did suffer a grievous injustice.

“They gave me some names of people. It is a matter of regret for me that this unfortunate man was shot and his family have suffered. But it is also a matter of disappointment that these matters have taken the twist they have taken.

“I have a very clear recollection [of how and when he was given the names]. This information was leaked (and) there has been reckless public commentary.”