SDLP MLA Justin McNulty said Paul Quinn’s murder was carried out by members of the IRA – the killing taking place 10 years ago today.
Mr Quinn, 21, was lured to a farm across the border in the Oram area of Castleblayney and beaten to death by a gang of men on October 20 2007.
Every bone in his body had been broken.
The murder was followed by a “collective cover up ... demanding an expertise to avoid detection combined with an imposition of fear in the community” said Mr McNulty.
“At the time Sinn Fein’s Conor Murphy sought to justify the brutality of the murder by callously brandishing Paul as a criminal. Conor was wrong and he has a duty to withdraw that slur on a murdered man’s name.
“Police services north and south contradicted Conor Murphy, as did the then minister for foreign affairs Dermot Ahern. Paul Quinn is not a criminal. His only offence was to stand up to the bullies Conor Murphy has sought to defend.”
UUP councillor David Taylor said PIRA members were responsible and the south Armagh brigade leadership would have had prior knowledge.
“Sinn Fein’s position on the Paul Quinn murder has not been credible to date,” he said. “I have no doubt that they possess relevant information in terms of the names of individuals involved which would serve as crucial in bringing the perpetrators of this heinous crime to justice.”
He fears the police investigation “is being impeded in the interests of political expediency”.
TUV leader Jim Allister said it was an IRA murder which “instantly gave rise to totally brazen and disingenuous spinning by Sinn Fein”.
He added: “Conor Murphy, who was then a Stormont minister, said that he had been to see the IRA leadership in south Armagh, which had given him ‘solid assurances’ that republicans were not involved.”
The police investigation and justice have been “sacrificed on the altar of the peace process” he added.
DUP MLA William Irwin said: “I would appeal to those who have even the slightest piece of information to provide it to the police on either side of the border.”
Meanwhile, the Garda has confirmed that 23 people have been arrested during the investigation into the murder.
The murder was carried out in the Republic of Ireland, where 14 people have been arrested. Nine people have also been arrested by the PSNI.
“From an investigative perspective, the investigation is still an active investigation which is now currently being reviewed by the Serious Crime Review Team and local detectives to review progress in the case, and to try to identify new avenues of inquiry,” a Garda spokesman said.
“Over 700 statements have been obtained by An Garda Síochána (AGS) and nearly 2,000 individual lines of inquiry have been pursued.
“It is the tenth anniversary of the murder of Paul Quinn and AGS are issuing a fresh appeal for information, in conjunction with Crimestoppers, and local and national media outlets.”
After the murder around a dozen signs appeared across south Armagh naming the alleged killers.
Former SDLP councillor Geraldine Donnelly lives only a few miles away from the Quinns, whom she had known long before the murder.
“They are just the nicest couple you could meet,” she said.
“What I can’t understand is that there was not one person among the 10 men beating Paul that would not step forward and say ‘enough is enough’ when they knew they had gone too far.
“He was a human being, a young light lad, only 21 years old.”