A Donegal man who was abducted and shot by dissident republicans has offered to testify in court against members of the Real IRA (RIRA) in the northwest.

In what security sources regard as an intelligence coup against dissident republicans, Liam McGinley, a father of six from Letterkenny, has also revealed the identities of the RIRA gunmen who murdered Denis Donaldson, the former Sinn Fein strategist who was shot dead at a remote cottage in Donegal in April 2006 after admitting he was a British spy.

McGinley is under garda protection, although it is not clear whether he has been formally admitted to the force’s witness-protection programme. A file that includes statements he made to gardai outlining his knowledge of the RIRA, and naming the paramilitaries who shot him, is being studied by the Director of Public Prosecutions.

McGinley agreed to co-operate after he was abducted, shot in the abdomen and dumped on a dirt track in the Derryveagh mountains in Donegal in November 2007.

He survived the attack and made his way to a nearby house whose occupants rushed him to Letterkenny general hospital. He was transferred to the Mater in Dublin where he agreed to co-operate with gardai in return for protection.

Security sources claim his decision to turn state’s evidence marks a breakthrough in the fight against republican terrorism in the northwest, a stronghold of the RIRA.

Although McGinley was never a member of the organisation, he had extensive contacts with the group’s membership in Donegal and Londonderry. Among them were senior terrorists suspected by gardai of organising attacks on the British security forces.

Garda sources emphasised last week that McGinley’s evidence was unlikely to lead to Donaldson’s killers being charged soon, but the force is confident of pressing some charges against three suspects involved in his shooting.

“He wasn’t present when Donaldson was murdered but has identified the killers and disclosed certain information on what happened to the weapon used in the killing,” said a source close to the inquiry.

Donaldson was murdered at a remote holiday home in Glenties. He was shot four times by an assailant armed with a shotgun. The first two shots were fired through the front door of his cottage as he attempted to bolt it or barricade himself inside. Once inside, his killers fired two more cartridges, killing him.

Members of the Provisional IRA were initially blamed for the murder but McGinley claims it was carried out by members of the RIRA from Londonderry. The organisation recently admitted it.

Originally from Scotland, McGinley grew up in Falcarragh but was not known to gardai as a serious criminal or a republican sympathiser. He was known in Letterkenny as a troublemaker who often appeared in court charged with public-order offences. In one incident, he was accused of threatening an undercover member of the garda drugs squad after being stopped and searched in Letterkenny.

RIRA, which murdered 29 people and unborn twins when it bombed Omagh in August 1998, has been repeatedly infiltrated by spies and informants since its formation in 1997. Paddy Dixon, a Dublin car thief who supplied stolen cars to RIRA in the months before Omagh, helped the gardai to intercept a series of bombs. He joined the state’s witness-protection scheme after his identity was accidentally revealed.

MI5 and the FBI also ran Dave Rupert, an agent recruited in America to infiltrate the RIRA. He appeared as a witness against Michael McKevitt, the founder of the terrorist group, helping to convict him on charges of directing terrorism.

General John de Chastelain, the head of the decommissioning body, will announce this week that Northern Ireland’s main loyalist paramilitaries have begun to decommission their weapons.

The groups involved are aiming to complete the process later this year. When they do, de Chastelain will give the British and Irish governments a full inventory of all decommissioned weapons, both loyalist and republican.

Loyalists’ plans to announce the move at a joint press conference were upset last week when reports leaked out that decommissioning had begun. The Ulster Volunteer Force and Red Hand Commando decommissioned the bulk of their joint arsenal two weeks ago.

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal