A west Belfast man allegedly tortured by paratroopers was plagued by nightmares more frightening than any real-life experience, the High Court heard.
Liam Holden told a psychiatrist there was no respite from dreams about the waterboarding techniques he claims were used in obtaining a false confession to murdering a British soldier 50 years ago.
During their sessions he stated: "When the nightmares are on, it's never done until I wake up. Even in my dreams I'm fighting them but I don't win.
"They always get me, the water goes in. I still feel to this day the water going up my nose."
Mr Holden, 68, was the last man in Northern Ireland sentenced to hang after being convicted of killing Private Frank Bell
The death penalty was commuted to life in prison before a 40-year fight to clear his name resulted in the murder conviction being quashed in 2012.
He has already been awarded £1m for losses suffered due to the miscarriage of justice.
Mr Holden is now seeking damages from the Ministry of Defence for alleged misfeasance in public office, assault and battery.
In 1972 he was arrested after Private Bell was shot in the Springfield Avenue area of west Belfast.
A teenage chef at the time, he was brought to a military post at Blackmountain school where members of the Parachute Regiment allegedly deployed banned interrogation techniques.
Soldiers pinned him to the floor and poured freezing water through a towel place over his face, he claims.
According to his account the repeated torture methods left him fearing that he was drowning.
He was then allegedly hooded and taken to the Glencairn estate, notorious at the time as an area where loyalist paramilitaries dumped murdered Catholics.
A gun was put to his head as the soldiers warned he would be shot if he didn't confess to killing Private Bell, Mr Holden contends.
He then agreed to a "cock and bull story" about carrying out the shooting.
The MoD is defending the action by denying liability.
One of the main witnesses is Dr Adrian Grounds, a forensic psychiatrist who examined the plaintiff in 2016.
The medical expert set out Mr Holden's account of suffering recurrent, unwanted thoughts.
During their sessions he stated: "There is no rest from it, I know before Saturday comes I will have a nightmare or a heavy-duty bad thought, but I won't tell anyone about them, I won't tell my kids.
"The soldier who did it, his face comes to me. I remember his features.
"Sometimes, a few times, I have nightmares of them pulling the trigger and I wake up. Then I have a hell of a time for a day or two after."
Mr Holden also stated: "Anything that happened to me in life hasn't been as frightening as the dreams, the nightmares."
The court heard he recalled the soldiers allegedly tapping a gun against the side of his forehead, adding: "I can still feel it."
Referring to his bogus admission, he went on: "It was like I was watching me. I know I haven't killed anybody, and yet they were so adamant."
According to Dr Grounds this recollection was a clear and striking statement of dissociation, where someone in a state of extreme anxiety and terror feel they are observing events which don't seem real.
At one point in their meetings Mr Holden became distressed and tearful, saying: "It kills me to think I could let them do it without a struggle."
Despite limited clinical experience in interviewing alleged torture victims, the psychiatrist that statement resonated with research literature about the "capitulation" of those subjected to waterboarding..
"The purpose is to break the will, and such techniques can induce a state of helplessness," he told the court.
"He reproached himself, how could I have let them do it without a struggle, and it fits with what I have read about experiences of this kind in other cases."
The case continues.