The son of a murdered prison officer has personally challenged Gerry Adams to name a former IRA leader who admitted the terror group carried out the killing.
Austin Stack confronted the Sinn Fein leader face-to-face in a Dublin hotel and called on him to give Garda information on the person who confirmed the shooting of his father Brian Stack in 1983.
The former Portlaoise chief prison officer was crossing a busy Dublin street after leaving a boxing contest when he was gunned down.
The IRA did not admit responsibility until 2013 when Mr Stack's sons Austin and Oliver were driven to a secret location in Northern Ireland with Mr Adams.
A statement was read to them by an unidentified former IRA chief.
During the election campaign earlier this year the Sinn Fein leader sent an email to Garda Commissioner Noirin O'Sullivan with the names of four people that he said Austin Stack had given to him in connection with the unsolved murder.
Mr Stack said the name of the unidentified IRA leader who they met should also be handed over.
"As a public representative you are an absolute disgrace," Mr Stack said.
"I am now putting firmly the ball in your court. Take the name of the individual that you know to An Garda Siochana."
Mr Adams rejected allegations that he had not told the truth in the Dail on Wednesday after being given the opportunity to make a personal statement on his dealings with Mr Stack's sons as they sought answers over their father's death.
"I just want to reject absolutely Austin's assertion that I have told lies or untruths," the Sinn Fein leader said.
"I'm quite content to co-operate with the Guards in all these matters."
Brian Stack was left paralysed and brain-damaged by the shooting and suffered for a further 18 months before dying from his injuries at the age of 47.
In the wake of Mr Adams' address in the Dail, two Sinn Fein TDs faced calls to make statements about the murder.
Martin Ferris, a former IRA gunrunner, and Dessie Ellis, who was convicted over Provo bomb offences, were named by Fine Gael TD Alan Farrell and urged to publicly comment on the killing of Mr Stack, a father-of-three.
Mr Ellis insisted he was in jail in Portlaoise at the time of the gun attack.
He challenged Mr Farrell to make accusations without parliamentary privilege.
Mr Ferris said he spoke to Garda detectives at their request three years ago about the murder inquiry and that he had nothing to answer for.
Irish Government chief whip Regina Doherty said Mr Adams was potentially obstructing the course of justice by not naming the IRA man that met the Stack brothers.