UUP peer Lord Laird has said he will name the killers of south Armagh man Paul Quinn using parliamentary privilege on Monday.
The 21-year-old was found at farm buildings near the village of Oram
Mr Quinn died after being severely beaten in County Monaghan last month.
His family said the IRA killed the 21-year-old after he had defied an order to leave the country. Sinn Fein denies any republican involvement.
"The IRA Army Council did not sanction the killing, but IRA members did kill Paul," Lord Laird told the News Letter.
"I will name names and lay-out all the information I have. We cannot allow this to be brushed under the carpet like Robert McCartney, the Northern Bank and Denis Donaldson.
"I am not just getting at Sinn Fein, but the security services, the government, the lot. I am deeply concerned at what appears to be a lack of progress by the security services on both sides of the border."