Despite claims by Sinn Fein President Gerry Adams that the IRA 'shot' paedophiles or rapists, the brothers - now aged in their 50s - were allowed to go free because they had close family connections to senior figures in the organisation.
Both were subsequently active in Sinn Fein, one holding office. Although rank-and-file party members might not have known about their background, their history was well known among senior IRA and Sinn Fein figures in Belfast. Their history was also well known to senior British security and RUC figures.
One former British security figure, speaking on grounds of anonymity, last night said the brothers were recruited as agents after it was learnt both were "of that type of bent".
The source used the same term that Gerry Adams used in the Dail last week about the way the IRA "resettled" abusers in relation to the brothers, though he had not heard Adams' speech.
A senior republican source told the Sunday Independent one of the brothers was known in west Belfast as a "kiddie fiddler", though he was never charged with any sexual abuse related offences or faced any sanction from the IRA other than exile to the Republic.
This brother was involved in serious offences including the murder of another IRA member suspected of being an informant for the Royal Ulster Constabulary (RUC). Despite this he was allowed to continue his activities in the IRA and free to continue his abuse of children, while working for British Army Intelligence.
He subsequently left the North in the late 1980s and 'resettled' in Co Louth, where he still lives. It is not believed he came to the attention of gardai.
The other brother was said to have been a lower level IRA member not involved in serious terrorism. He too was 'resettled' south of the Border after a complaint was made by one of his victims but subsequently returned to Belfast.
Both were identified as paedophiles by the British intelligence services and "turned", the term used for recruitment as agents within the IRA, the security source told the Sunday Independent.
He said one brother was "turned" after a collection of paedophile pornography was found in his home. The source said it was known there was a history of abuse in the brother's family background.
The source added: "On the (mother's family name) side of the family there would have been others, I think from memory, who were guilty of the same thing. In some ways it was seen as a tool which could be used to exploit somebody. Both worked for FRU (Force Reconnaissance Unit, the British Army's secret undercover unit in Northern Ireland). "I know (name of one of the brothers) had a penchant for child porn. They were both into that type of bent, for want of a better word.
"Both (the names of the brothers) were well known about within the Republican Movement. (Name of one of the brothers) was moved to Newry and, from memory, there was a bit of a bad reaction there because they knew he was a 'kiddie fiddler' and they moved him to Dundalk."
The brothers escaped execution by the IRA once it learned both had been recruited as agents because of their family connections.
One of the brothers was subsequently allowed to return to Belfast.
A former senior IRA figure told the Sunday Independent: "Yes, it was well known" that the brother who was more seriously involved in IRA terrorism was, in his words also, a 'kiddie fiddler' and: "a "Brussel, ('brussel sprout', the Belfast slang term for a 'tout' or informant) for (expletive) sake, everyone knew that."
The Sunday Independent previously revealed how another Sinn Fein figure, subsequently well known in the North, who was similarly "turned" by the RUC Special Branch after they secretly filmed him having sex with his niece who was aged only 13 or 14 at the time. The abuse was said to have taken place in a caravan used by Sinn Fein as a polling office during elections in the North in the 1980s. The video tape is said to have been explicit and watched for entertainment by Special Branch officers. This man remained in Northern Ireland.
The former British intelligence figure also revealed that one of their own agent handlers was caught "taking pictures of kids" at a location in Co Armagh. "We had our own bad apples," he said. "It wasn't just in the Republican Movement. You get it in all walks of life."
A separate republican source said another Sinn Fein figure was 'resettled' in the Republic after it was alleged he had raped a young IRA woman at a party on the night she was released from a jail term for explosives offences. The boyfriend of another IRA woman prisoner who complained to Sinn Fein was badly beaten by an IRA squad with iron bars and hurleys.
The British security services and the IRA could both come under the spotlight if, as suggested by the North's Deputy First Minister Martin McGuinness last week, a commission of inquiry is set up to investigate the movement of abusers across the Border.
Blackmailing gays, pedophiles and other perverts was a common occurrence during the 2nd World war and the subsequent cold war. MI5 often used such people as agents or double agents against communist intelligence. It is no stretch to see it used by the Army and the RUC in its struggles with the IRA.
It's still very disappointing that they considered the children to be acceptable, collateral damage in their operations. As we see by the Special Branch officers choice of entertainment, they were not much better than those they blackmailed.