EXCLUSIVE: CLASSIFIED documents stolen during the break-in at Castlereagh have shown the IRA 'commander' at the time of the Shankill bomb was working as an informant and passed information to his handlers that could have potentially prevented the atrocity.
The former 'blanketman', now aged in his late 50s, was known as agent AA and calls made to his special branch handlers are logged throughout the documents stolen by the IRA during the raid at PSNI headquarters almost 15-years ago.
The files stolen during a robbery on St Patrick's Day 2001 were heavily encrypted had to be deciphered by the IRA who used a handful of trusted members to decode the information.
The north Belfast man was 'stood down' by the organisation's ruling army council in 2002 after they pieced together the coded information and discovered he had been working as a double agent for almost a decade.
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However, the Irish News understands that while he was replaced by high profile republican Eddie Copeland, no explanation was given to the rank and file members as the leadership attempted to keep the information under wraps.
The IRA man has managed to evade the spotlight for almost two decades despite leading the deadly Ardoyne unit of the paramilitary group during a period when they were involved in numerous shootings and bombings.
The most high profile of which, the 1993 Shankill bomb, led to the deaths of nine civilians, including two children and one of the IRA bombers Thomas Beagley who also died in the blast.
The Police Ombudsman has now been asked to investigate allegations that police were in possession of information that could have prevented the atrocity.
The complaint has been made by a family member of one of the victims.
A solicitor acting for the relative confirmed to the Irish News: "The family I represent have instructed me to lodge a complaint with the Ombudsman".
The complaint was lodged on Friday.
The Irish News has seen documents which show the Ardoyne IRA chief was in contact with his handlers in the run up to the bombing and passed on details of 'scouting missions' to the Shankill.
Plans to kill UDA leader Johnny Adair in his office, situated above Frizzell's fish shop in the weeks leading up to the bombing were known to special branch who were receiving regular information from AA.
Prior to placing a bomb in the shop several different plans to kill the leading loyalist were considered. Details of calls made at this time by the agent known as AA appear on the stolen Castlereagh files.
On the day of the bomb the office above the shop was empty and no UDA members were caught up in the blast that injured over 50 people.
The atrocity caused public outrage and resulted in a series of revenge attacks by loyalist paramilitaries - including the Greysteel massacre a week later - and forced all sides back to the negotiating table.
Less than 10 months later the IRA called a ceasefire.
The year after the atrocity former UUP leader David Trimble used parliamentary privilege to name Copeland as having planned the attack during a debate on the renewal of anti-terrorist powers. Two other alleged IRA men were also named.
However, 'AA' who was the acting IRA 'commander' at the time was not named publicly and until now has remained virtually anonymous.
While he remains at his home in the staunchly republican Ardoyne area in recent years he has become almost reclusive.
He refused to attend a controversial commemoration in memory of Thomas Beagley on the 20th anniversary of the blast in 2013.