One of the men named in the House of Lords in connection with the murder of Paul Quinn yesterday challenged his accuser to repeat the claims in public.
Vincent Treanor spoke out after Ulster Unionist peer Lord Laird claimed he was linked to the killing.
On Monday, Lord Laird told the House of Lords that the killing had happened following a dispute between Mr Quinn and a son of Vincent Treanor, "a local IRA chief". Lord Laird said Mr Treanor had "talked the leadership in south Armagh into a situation which saw the brutal and savage murder of Paul Quinn".
He said Mr Quinn and some other youths from the area had been "involved in activities which did not go down with the senior republican leadership in south Armagh" and claimed that "several weeks ago, Treanor asked the republican leadership . . . to have Quinn executed".
Mr Treanor, from Cullyhanna where Mr Quinn also lived, denied ever being a member of the IRA or having anything to do with Mr Quinn's death. He said: "I totally refute the comments of John Laird that I am a local IRA chief".
The 21-year-old victim was beaten to death by a gang of men after being lured across the Border to a farm's outbuildings in Co Monaghan last month.
Although Sinn Féin categorically denied republican involvement in the killing, the Independent Monitoring Commission has indicated that either current or former IRA men may have been responsible.
But in a statement issued through Belfast solicitors Madden & Finucane, Mr Treanor hit back at the allegations against him.
He said: "I challenge John Laird to state his lies publicly and subject them to challenge through the courts."
Mr Treanor also insisted there was no row between his son and Mr Quinn before the killing. "I have lived for 30 years in Cullyhanna and am widely known locally," he said.
"I have had no involvement in the death of Paul Quinn. I am not and have never been a member of the IRA. I have never been arrested or charged with this or any similar offences."
Mr Treanor added that he was aware of graffiti in the area linked to the murder, and that police have warned him of a possible threat to his life.
"I am aware that a number of people have also been named locally as involved in the death of Paul Quinn. I have no involvement with these people," he said.
"I can say that there has been no dispute, row or altercation of any kind between my son and Paul Quinn. My son works away from home during the week and returns home only at the weekends."
Mr Treanor described the murder as a horrific crime and called for those responsible to be brought to justice.
He said: "I condemn those who seek to make political points out of this tragic death."