Paratroopers allegedly used waterboarding torture techniques against a West Belfast man to extract a false confession to the murder of a British soldier, the High Court has heard.
Liam Holden also claimed he was hooded and had a gun pointed at his head before he falsely admitted to shooting Private Frank Bell 50 years ago.
Mr Holden, 68, was the last man in Northern Ireland to be sentenced to hang.
The death sentence was commuted to life in prison before a 40-year fight to clear his name resulted in his 2012 murder conviction being overturned.
He has already been awarded £1m for losses suffered due to the miscarriage of justice.
But Mr Holden is now seeking damages from the Ministry of Defense for alleged misdeeds in public office, assault and battery and torture.
In 1972 he was arrested after Private Bell was shot dead in the Springfield Avenue area of West Belfast.
A teenage leader at the time, he was brought to a military post at Blackmountain School where members of the Parachute Regiment were said to have deployed forbidden interrogation techniques.
The soldiers pinned him to the ground and placed a folded towel over his face, the court heard.
Mr Holden said: “They started slowly pouring a bucket of water through the towel.
“The first thing I felt was cold, then I tried to breathe, then I sucked water through my mouth and through my nose.
“It was as if you had just drowned.”
He described being revived and slapped across the face as soldiers held him by the armpits.
Up to four interrogation and waterboarding sessions were reportedly conducted.
At that point he was hooded, dragged on a chair and taken to a loyalist area of Belfast.
“While we were driving, one of the soldiers was hitting me on the knee with a gun saying, ‘This is for you’,” he recalls.
“They took me to Glencairn, a notorious place for Catholics found shot dead.
“They took me out of the car and took me to a field, put a gun to my head and said if I didn’t admit to shooting the soldier, they would shoot me.”
Asked by his solicitor, Brian Fee QC, how he responded to the alleged threat, Mr Holden replied: ‘I just said I shot the soldier.
According to his account, he was then taken back to Blackmountain, where the hood was removed and offered a cup of tea by a senior officer.
“He basically said to me ‘you realize we have to do these things,'” Mr Holden added.
“After that I said I shot the soldier, I made a rooster and bull story about where I shot him from, where I got the gun, where I threw the gun and how I got away. Just a bunch of bullshit.”
The MoD is defending the action denying any liability.
The case continues.