A number of republican terrorists have broken away from the main dissident groups amid growing suspicion they have been heavily infiltrated by the security services.
Members of renegade groups such as the Real IRA or Continuity IRA have become nervous that they have been penetrated by security agents after police thwarted a number of potentially deadly attacks, including the attempted murder of a student officer in Garrison, Co Fermanagh, in November.
A security source in the North said: “There is a lot of suspicion within these groups that someone within the ranks is spying and spilling the beans so some have decided to break away to stay under the radar.
“They think they will have a better chance that way and that there will be less chance of an informer touting.”
The source added that MI5 has been working with an intelligence unit in the PSNI to prevent a number of suspected terrorist plots.
There has been speculation that one of the plots halted by police and MI5 was the bombing of the Policing Board headquarters in Clarendon Dock, Belfast, late last year.
The 400lb bomb, which was left outside the building after two men drove through a barrier before fleeing the scene, only partially exploded leading to speculation that the device may have been “tampered” with by the security forces. If it had fully exploded the bomb would have caused major damage.
Prior intelligence of the attempted murder of a newly recruited Catholic PSNI officer in his home in Garrison also meant that police were able to lie in wait for the gunmen when they arrived.
The threat from dissident republicans has been steadily increasing over the past year as they become more organised. They have increased in number and have been receiving help in bomb- making and surveillance techniques from disaffected former IRA members.
They are also believed to have substantially increased their weapons arsenal over the past 12 months.
The dissidents are carefully choosing their targets and it has been claimed the recent targeting of high-profile figures, such as the governor of HMP Maghaberry and a senior judge, shows a greater level of sophistication within the groups.
The discovery of former Maghaberry governor Steve Rodford's personal details in a prison cell and the targeting of Mr Justice Seamus Treacy's home in north Belfast appear to mark a new direction in the dissidents’ campaign.
More than 20 police officers and their families have had to abandon their homes in the past six months and relocate at secret addresses after intelligence showed they were dissident republican targets.