The New IRA was told two years ago that the suspected informant who is now accused of setting up senior dissident republicans for arrest at bugged safe houses was in the pay of the security services.
They dismissed these claims because the individual, who fled his home last week prior to a series of high-profile arrests, was close to leading west Belfast republican Tony 'TC' Catney.
The convicted killer and former Provo life sentence prisoner, who died from cancer in 2014, helped form the New IRA.
It was because of Catney's endorsement that the agent, who was born in Britain, was welcomed into the ranks of the terror gang.
Sinn Fein sources denied claims the agent was ever a member of the party before aligning himself with dissident groups but said he was involved in republican campaigns over the years. The contents of his home were packed into a removal van on Wednesday.
Sunday Life can reveal that his role was to provide safe houses in which the New IRA would meet to plan attacks and discuss strategy.
The two properties at the centre of the case against the nine suspects in custody are in the village of Gortin and in a rural cottage near the Ballinderry River, both in Co Tyrone.
At least one of the houses was secured on the website booking.com. There is no suggestion the owners of these properties or those involved in the website had any idea what they were being used for.
It was here that leading dissident republicans Paddy McDaid (50), Gary Hayden (48), Kevin Barry Murphy, Davy Jordan, his wife Sharon Jordan and Mandy Duffy (who are all in their 40s) as well as Damien 'DD' McLaughlin (43), Joe Barr (31) and Shea Reynolds (26) are accused of masterminding a terror campaign.
Reynolds and McDaid were remanded in custody following a court appearance yesterday at which they were charged with New IRA membership and directing terrorism. Last night Gary Hayden was charged with directing terrorism, membership of an outlawed organisation and two separate charges of preparatory acts of terrorism. He is in court tomorrow.
The others continue to be questioned by detectives along with a 62-year-old Palestinian man who was arrested at Heathrow Airport, with follow-up searches carried out on a property in Edinburgh. Sources said he is suspected of links to the Popular Front for the Liberation of Palestine group.
PSNI Crime Operations Assistant Chief Constable Barbara Gray confirmed he was arrested under the Terrorism Act, saying: "The man, who resides in Scotland and was arrested as part of Operation Arbacia, has been brought to Northern Ireland and is currently in Musgrave Serious Crime Suite, where he is being questioned."
The MI5-led operation has struck a hammer blow against the New IRA and its political wing Saoradh, six of whose members are in custody.
At the heart of the probe is the man both organisations have identified as a double agent and who they accuse of infiltrating the New IRA for the intelligence services. His role was to supply safe houses for the gang to hold 'army council' meetings at which targets and strategy were discussed. The properties were bugged by MI5, with high-powered cameras and listening devices placed in rooms throughout.
Sunday Life understands that after renting the homes the agent told New IRA leaders to park in rural locations nearby. He then taxied them to the properties in his own car, taking them back to their vehicles after the summits.
It was during these return journeys that MI5 operatives descended on the houses, removing coffee cups, cigarette butts and other items laden with DNA evidence to back up their recordings.
Sources told this newspaper that "weapons, recruitment, international links, changes to the New IRA constitution and interrogation techniques" were among the topics discussed.
Each of those present introduced themselves by rank, with Kevin Barry Murphy understood to have described himself as "chief-of-staff". The Coalisland man was previously referred to in security files as having "a long history of active involvement in republican terrorism".
Murphy's pal Davy Jordan, who served separate prison sentences for possessing firearms, is reported to have called himself "chairman of the army council". His wife Sharon Jordan, formerly Rafferty, was previously jailed for her role in a dissident training camp in Tyrone.
Both men are understood to complain about the lack of support the New IRA has in Tyrone and how locals continue to contact former Provos when they want a dispute resolved. They also accuse a prominent republican, who has drifted away from dissidents, of refusing to hand over weapons to them to use in 'operations'.
This discord within the New IRA can also be seen in conversations those from Derry had among themselves, with senior members such as Thomas Mellon refusing to attend summits and no one from Belfast being invited.
Those present also go to great lengths to use their knees, feet and elbows to open doors in an effort not to leave fingerprints, but these security concerns do not stretch to coffee cups and cigarette ends left lying around.
During one conversation they even joke that the house might be bugged, oblivious to the fact they are the targets of a sophisticated M15 sting operation.
The New IRA has been a key focus of the security services since its murder of journalist Lyra McKee during a riot in Derry last year.
Its leaders have known for some time that it has been heavily infiltrated, with a series of botched murder bids evidence of this.
In the space of 48 hours last September, police discovered two bombs in Strabane and Derry primed to kill officers.
This came after a mercury-tilt switch device, which was found under a top PSNI officer's car outside Shandon Park Golf Club in east Belfast, failed to detonate despite the vehicle being driven over six ramps. Prior to this, four similar devices fell off the underside of cars belonging to serving cops and soldiers.
In June police recovered the gun used to murder Lyra McKee, with DNA evidence from it leading to Niall Sheerin (27) being charged with possession. Derry New IRA chief Thomas Mellon had assured the gang's leadership the weapon had been discarded, with the row that followed leading him to temporarily quit before rejoining the group.