The parents of Paul Quinn, who was beaten to death by the IRA in south Armagh in 2007, have called on Gerry Adams to withdraw the Sinn Fein "slur" against their son that claimed he was a criminal.

And they challenged Mr Adams to give gardai all the information he has about the slaying of their son.

Sinn Fein actively prompted journalists to believe the 21-year-old was killed purely as a result of criminal activity in south Armagh.

He was lured to a farm near Oram, Co Monaghan, where a dozen masked men wearing black military-style clothing lay in wait.

The Cullyhanna man was beaten with iron bars and nail-studded cudgels.

Every major bone in his body was broken - his hands so badly deformed that his parents were unable to place a set of rosary beads into them.

He died in hospital shortly after the savage assault on October 20, 2007.

Although more than 20 people have been arrested during the Quinn murder investigation - including Padraig 'Paudie' Treanor, a former driver of Sinn Fein Newry and Armagh MP Conor Murphy. None has been charged.

In the Paul Quinn case, gardai firmly believe he was beaten to death for "disrespecting" a local IRA leader who, they say, is also a locally well-known Sinn Fein activist.

Paul's parents, Breege and Stephen, are now asking for a meeting with the Sinn Fein leader so that he can withdraw his party's branding of their son as a criminal. They pointed out that Paul had no money and owned a car worth only around £100 when he was murdered, beaten to death by a gang of well-known south Armagh IRA men.

Similarly, in another sinister case of paramilitary murder, Sinn Fein sources in Dublin blackened the name of Joseph Rafferty.

He was another entirely innocent young man who was shot dead in April 2005 by the IRA.

The Quinn family's call comes amid renewed garda activity in the seven-year long investigation following the arrest of two men in Northern Ireland over the January, 1999 murder of another man, Eamon Collins. That killing is believed to have been carried out by the same gang that murdered Paul Quinn.

Both murders were marked by a degree of savagery which left even experienced detectives stunned.

Gardai believe both murders were ordered by the Provisional IRA's OC (officer commanding) in south Armagh, Peter John Caraher, who died three years ago.

Gerry Adams was well acquainted with Caraher and gave the oration at his burial in Cullyhanna in October, 2011.

He described Caraher as "a giant through our Troubles, a steadfast republican" and described him as "OC" of the south Armagh IRA. He also described Caraher as "a deeply religious man, a committed republican, a life-long pioneer, a member of the Lourdes committee".

But other republican sources described Caraher as a corrupt bigot who had given the order for the mass murder of 10 Protestant workmen at Whitecross in south Armagh in January, 1976 in retaliation for the loyalist murders of Catholics.

Caraher was not present but is believed to have given the go-ahead for the murder of Paul Quinn after the young man had "disrespected" another local IRA boss.

Belfast Telegraph