A former Justice Minister has accused the Provisional IRA of still lying, after they finally admitted last week their part in the murder of a prison officer in the Republic three decades later.

Fianna Fail’s Willie O’Dea said the IRA statement to the family of prison officer Brian Stack that maverick members killed him was a false excuse in the hope that Sinn Fein could walk away from their responsibilities in the murder.

O’Dea maintained that exactly the same lies were told about the murder of detective Gerry McCabe during an IRA Post Office robbery in 1996.

O’Dea told the Sunday Independent that statements from the IRA last week accepting responsibility, but by maverick members, for Brian Stack’s murder outside the national Stadium in Dublin showed “no one’s grief, tragedy or sadness is so great that it cannot be used by Shinners and Provos for their own advantage.”

Stack, chief prison officer at Portlaoise Jail which housed Republican inmates, died 18 months after he was shot in the back of the neck outside the National Stadium in Dublin in 1983.

His sons, Austin and Oliver received a statement after a secret meeting with a former IRA leader last week arranged by Sinn Fein TD Gerry Adams.

The former leader, who was unmasked and used the single name, John, said: “I want to acknowledge that the IRA was responsible for the death of your father. I regret that it has taken so long to clarify this matter for you.”

He said the killing “was not authorised by the IRA leadership and for this reason the IRA denied any involvement.”

Austin Stack said the family had achieved some closure from the IRA’s admission, but added: “I still want to meet face to face with my father’s killer.”

Adams has insisted that he hadn’t known the IRA carried out the shooting. He said he still didn’t know who pulled the trigger. He told the Irish Independent: “I didn’t ask and I don’t intend to.

“On behalf of Sinn Fein, I extend my regret at the killing of Brian.”

Justice Minister Alan Shatter said the IRA admission was “30 years too late."

Oliver and Austin Stack, sons of Brian the prison officer murdered by IRA, speak to the press outside Leinster House, in DublinRTE