RELATIVES of those killed in the 1971 McGurk’s Bar bombing in Belfast are launching legal action to force a fuller disclosure of official documents amid longstanding suspicions of British state collusion in the attack.

Fifteen people died and 17 were injured in the blast after a bomb planted by the Ulster Volunteer Force (UVF) exploded at the height of the Northern Ireland conflict.

British government files showed that the army and Royal Ulster Constabulary (RUC) lied to Downing Street in the immediate aftermath of the attack, blaming it on the IRA.

The papers showed that military propaganda outfit Defence Secretariat 10 blamed innocent victims just hours after the explosion.

General Sir Frank Kitson, who was a brigadier, and the RUC were accused of colluding to smear the pub as a known haunt of senior IRA figures.

A stepson of Thomas McLaughlin, who was killed in the blast, is taking legal action against the Ministry of Defence, PSNI and Police Service and Secretary of State.

While a civil case is ongoing, proceedings have been delayed through a continued failure to disclose documentation to the victims’ lawyers.

Eoin Murphy, of O’Muirigh Solicitors, said: “There have long been suspicions of security force involvement in this atrocity.

“This is reinforced by the catalogue of documentation which has been uncovered to date,” he said.

“The families know that there are undoubtedly hundreds if not thousands of discoverable documents currently retained by the defendants which are linked to the murders of their loved ones.”

The McGurks Bar Campaign for Truth said: “The perfidious British government wants to bury its war crimes in Ireland and protect its killers.”

A spokesman for the British government said: We don't comment on ongoing legal proceedings."