A former IRA member linked to the murders of three off-duty Scottish soldiers in north Belfast almost 50 years ago is still on the run in the Republic of Ireland, a BBC Spotlight investigation has established.
ougald McCaughey (23) was killed alongside brothers John (17) and Joseph McCaig (18) on March 10, 1971.
The 1st Battalion, Royal Highland Fusiliers had been stationed at Girdwood barracks and were out socialising in Belfast city centre when they were lured to the remote White Brae on the Ligoniel Road by republicans and murdered.
No one has ever been convicted over the killings.
Police have long suspected IRA men Patrick McAdorey and Anthony 'Dutch' Doherty of being involved.
McAdorey was shot dead by the security forces in August 1971 before he could be charged.
Doherty escaped from Crumlin Road Gaol, where he had been interned, in December 1971 and went on the run in the Republic of Ireland.
A BBC NI Spotlight documentary aired last night, The Killings of the Three Scottish Soldiers, revealed that despite some believing that Doherty was dead, he is alive and living in Dublin.
When approached by Spotlight, he "vehemently" denied being involved in the killings.
The programme reported he was arrested in 1971 and confessed when questioned by Metropolitan Police detectives.
But a judge later found the process of interrogation at the time meant admissions could not be regarded as voluntary.
Paddy O'Kane, who had served seven years in the Parachute Regiment, was also named in the programme as being centrally involved in the killings.
The former soldier, now deceased, is reported to have befriended the three Scots before they were led to their deaths.
A former IRA member and members of O'Kane's family confirmed that he said he played a key role in the killings.
O'Kane, who was from north Belfast, joined the Parachute Regiment in 1957 and served in Jordan and Cyprus.
He left the Army in 1964 with a "very good" service record and joined the Provisional IRA at the outbreak of the Troubles in 1969.
O'Kane was identified by police as a prime suspect in the killings almost immediately after they were carried out, although he evaded arrest and went on the run in the Republic.
Former IRA intelligence officer Kieran Conway said O'Kane spoke openly about his involvement in the murders.
"I believe any man that could execute three young Scottish soldiers in that manner must have been a psychopath," he said.
The programme also reported that O'Kane was a lead suspect in the 1976 Kingsmills Massacre, in which 10 Protestant workmen were shot dead by the IRA.
He was granted a controversial on-the-run letter in 2007, after previously being refused in 2003, which confirmed he was not wanted by police in connection with any crime.
O'Kane died in March 2009 in Shannon, Co Clare, where he had lived since 1976.
His sons told Spotlight he spoke "matter of factly" just once about what had happened.
The programme linked a fourth republican, Harry Canavan, with the killings. He is now also deceased.
The murders led to widespread revulsion across the UK, particularly because the soldiers were off-duty and in civilian clothes at the time.
In response it was announced that security arrangements for off-duty soldiers would be reviewed.
The bodies of the three soldiers were found by 14-year-old Brenda Kielty, who has only spoken publicly once about what she witnessed.
"They were just shot and dumped on top of each other. I didn't know whether it was three Protestants or three Catholics, but I never dreamt it was three soldiers," she said in 2017.
"There was nothing to indicate that it was three soldiers."