The son of a murdered RUC officer has claimed the Police Ombudsman's office is delaying publication of a report into his father's death because it could be politically explosive.
Gavin Larmour, whose father John was shot dead by the IRA in a Belfast ice cream parlour in 1988, believes the killing was not properly investigated to protect a high-level republican informer.
He claimed that the senior Provisional, who sat on the IRA army council in the 1990s and is a former Belfast Brigade commander, was recruited as a police agent after detectives presented him with evidence that would have led to his conviction for the murder.
The Ombudsman has already found that the RUC did not thoroughly investigate the killing. But Gavin said that an Ombudsman investigation into the police's actions has taken more than a decade to complete.
"I'm told that the report is finished but that it mightn't be published until the end of the year," Gavin added. "I'm not even hopeful of that as deadline after deadline has already been broken. I fear that the delay is for political reasons because the findings are just too explosive. That may sound overly suspicious, but, given my experience, I've every reason to be suspicious."
A spokesman for the Police Ombudsman said: "The investigation is now complete and will be published in the latter part of this year."
Gavin, who was just 13 years old when his father was shot dead, told the Belfast Telegraph how he had been fighting for justice for his dad since he was a teenager.
"I will be 42 next year, the age my father was when he was murdered," he said. "Nobody has ever been charged with his killing, but I've served a life sentence.
"I have had to become a detective myself, piecing together bits and pieces of information about the murder, chasing the facts, because the authorities just weren't interested.
"My father gave his life to the RUC, but they failed him, and the PSNI are failing me now. In simply seeking the truth, I have come up against brick wall after brick wall. But I will not stop - my father is gone, but I am his voice and I will be until the day that I die."
John Larmour was working in his brother's ice cream parlour, Barnams, on the Lisburn Road in October 1988 when two IRA men entered the premises.
One remained near the door while the other walked to the counter. He asked if the shop served chocolate ice cream and ordered "two sliders".
As the off-duty police officer served him, the man pulled a gun and shot him, and the other gunman fired at two customers in the shop. Constable Larmour died at the scene.
Gavin named the senior Provisional he believes killed his father. He claimed the IRA unit used a safe house that had been provided by estate agent and Special Branch informer Joe Fenton. The premises were bugged by the security services.
It is alleged that, several months later, detectives presented John Larmour's killer with taped evidence of his involvement in the murder. Gavin claimed that the top republican then agreed to become an informer and was paid £65,000 by Special Branch for doing so.
The IRA man from west Belfast is in his late 50s. He was one of the first Provisionals on the scene after the murder of Gerard 'Jock' Davison in the Markets area of the city last May. He was also involved in numerous IRA murders carried out in the mid to late Nineties under the Direct Action Against Drugs cover name.
Gavin alleged that this man was further involved in the 1988 murder of loyalist Colin Abernethy, who was shot dead on a train in Finaghy - using the same gun that killed his father - and in the murder of leading loyalist Ray Smallwoods, who was gunned down outside his Lisburn home weeks before the IRA's 1994 ceasefire.
As Belfast Brigade commander, the republican named by Gavin was responsible for high-profile bombings that devastated Belfast city centre in the 1990s. After the ceasefire he was regarded as a militant critic of the Adams-McGuinness faction.
However, at a key IRA convention in 1997, when he was expected to support a hardline challenge led by quartermaster general Michael McKevitt, he dramatically changed sides at the last minute and supported the leadership.
Gavin claimed that the man's alleged role as an informer had protected him from prosecution.
"I don't believe he will ever face justice in a court," he said. "I am totally disillusioned with the system. It seems a sham to me."
Gavin revealed how it was himself, and not police, who tracked down the two weapons used by his father's killers. They were found hidden along the border in Belgium in 1990. The IRA had taken the Browning pistol from Corporal Derek Wood in Andersonstown in March 1998. After being used in the ice cream parlour attack, the gun was employed by the IRA in operations in Germany. The Belgian police handed it over to the Germans. It is currently held in a forensic science laboratory in Baden Wurttemberg. After years of handling by others, DNA recovered now from the weapon would be of no evidential use.
The Ruger six-speed with which Constable Larmour was killed was later used in Holland by the IRA to murder two Australian tourists they mistook for British soldiers. It was sent to Holland for forensic examination and, after Gavin's intervention, eventually passed on to detectives here.
It was one of 7,346 Rugers that the RUC issued to officers, but it cannot be traced further because records no longer exist.
Gavin does not believe speculation that it is the same gun that the IRA recovered from loyalist Michael Stone after he opened fire on republican mourners at Milltown Cemetery in 1988. He also said it was disgraceful that the Ruger was returned here only after his intervention.
"If police here had asked for it earlier, I believe stronger DNA samples could have been secured," he added. "My whole experience is that there has been no investigation into my father's murder. Anything that has happened has been driven by me. Information was routinely blocked, or withheld, by Special Branch."
Gavin said that his father's murder had taken a huge toll on his physical and mental health, and he recalled how police officers had arrived in the middle of the night to break the awful news to his mother.
"Mum let me sleep. I got up for school the next morning to be told: 'You're staying at home today... your dad has been shot dead'. I felt like my world had ended," he explained.
BBC footage from the time shows the 13-year-old in his school uniform, wiping the tears away with a handkerchief. "I don't remember that day - it's all a blur," he said.
Gavin suffered severe depression after the murder and developed psoriasis due to the trauma.
"I still suffer from the condition - it's so bad that I need chemotherapy to control it. I didn't have a normal adolescence," he told this newspaper.
"From I was 16 years old, I was ringing up the Chief Constable's office, asking them questions. I have been at this a quarter-of-a-century. I've travelled to Holland to talk to the police there. I've gone to London to meet legal experts. I've traced as many of dad's colleagues as possible to find out what they knew.
"I've made the phone calls, knocked on doors and got on planes because the police, as an organisation, didn't do their job. There is all this lip-service paid to victims, but no practical help was ever given to me. I wasn't even offered counselling.
"My dad's inquest took place eight months after he was killed. My mum and I weren't even informed that it was happening. We had to pay to get a copy of the transcript."
Gavin grew up knowing the risks his father faced as a policeman.
"If he was driving and he became suspicious of a car nearby, he would tell me to take down its registration number. All those things were part of my childhood," he said.
Physically, Gavin is the image of his father. "My dad and I were really close," he said. "I remember little things like going to watch football together and getting chicken and chips on a Saturday.
"Dad was very sporty. He taught me how to swim and to play golf. I wish he was here now so we could have a game together, and maybe I'd beat him and make him proud that he taught me so well."
On Sunday Gavin will take part in a very special competition in memory of his dad.
"I am playing at Ballyclare Golf Club - where my father was a member - for the Larmour Cup, which is named after him," he explained. "I was robbed of getting to know dad, so I love meeting those people who did, and hearing their stories.
"I miss him more than words can say. I have so many lost years. Talking to others about him helps fill in the gaps."