There have been calls for an investigation into whether a Crown force informer in the north of Ireland was allowed to continue to engage in child sex abuse in exchange for spying on the INLA, the Irish National Liberation Army.
Relatives of the victims - a girl and her brother who were raped and abused in the early 1990s - believe their attacker was protected because he was an INLA informer.
The Irish News said it was told that the INLA was unaware of his activities, but that if the disturbing details had come to light before their 1998 ceasefire “he would have been executed”.
The man from Derry was found guilty of abuse at Coleraine Crown Court along with his brother.
The verdict followed a three-week trial in which his daughter gave distressing evidence about her ordeal at the hands of her father and uncle. She told the court she was raped up to a 1,000 times during weekend visits to her father after her parents split up.
The man, who cannot be named to protect the identity of his victims, was found guilty of 31 sex offences against both his children, including six counts of raping his daughter.
Amid other disturbing details, the court heard how she was raped at first by her father before his brother joined in after playing cards along with other unidentified men.
In 1998 a file was sent to the Director of Public Prosecutions but no further action taken after it was decided there was not enough evidence to pursue criminal proceedings.
Relatives of the victims have now called for an investigation into how he had escaped justice for so long, saying they believe he was working as an informer.
The man is understood to have had no direct involvement with the INLA since the early 1990s and had gone undetected.
One said that he “was certainly not offered any protection from the organisation... in fact had we been made aware of this before the cease-fire he would have been executed”.
The news emerged as the 20th anniversary of the killing of a former INLA leader was being organised in County Derry. Several hundred people turned out to mark the anniversary of the killing of Dominic McGlinchey.
Saturday’s event, which was organised by the Irish Republican Socialist Party (IRSP), was marked with a parade led by a colour party through Bellaghy to his graveside.
Mr McGlinchey is buried along with his wife Mary, who was also an INLA member. She was shot dead in front of her two sons Dominic and Declan in Dundalk, Co Louth, in January 1987.
No-one has ever been charged in connection with either killing.
In his oration, IRSP member Paul Gallagher said Dominic and Mary suffered a lot personally through imprisonment and being on the run.
“In reality they only had a few short years together. But their love and their bond was unbreakable,” he said. “We in the RSM are bursting with pride to have had such leaders and the debt we owe them is immeasurable...”
“We will never forget or forgive the counter revolutionaries and those sinister hidden hands who took their lives.”