The Security Service MI5 is monitoring a former senior IRA figure amid fears he could join the dissident war.
Sources are not yet able to say if the Tyrone republican had any link to the weekend bombing that claimed the life of Catholic police constable Ronan Kerr.
But they know the one-time IRA leader has the ability to mount such an attack.
The type of device placed under the young officer’s car was used throughout the IRA ‘war’. It contained a small quantity of high explosives, and was fitted with a tilt switch and safety timer.
Any move by the former IRA figure and his supporters into that dissident world would significantly enhance the threat posed by the different armed factions – a threat already assessed as being severe.
All of the dissident groups would want his services and war know-how.
The Tyrone republican has publicly criticised the Sinn Fein peace strategy – and specifically its endorsement of policing.
His identity is known to the Belfast Telegraph, but we are not naming him at this stage.
Speaking to the newspaper, a source confirmed that MI5 has had him under surveillance for weeks – monitoring his movements and meetings and trying to work out his intentions.
He is said to be close to a border-based dissident leader who sits on the so-called army council of the faction Oglaigh na hEireann. Of all the dissident groups, it poses the most serious threat.
Over the past year or so, it has used under-car booby trap bombs to target constable Peadar Heffron, an Army major and a PSNI officer who is a dog handler.
In its intelligence assessments MI5 will be trying to answer a number of key questions.
Specifically on the weekend bombing, it will want to know if the former IRA figure was involved – either directly or by offering bomb-making expertise or explosives.
But even if he was not involved, there is a concern he could join one of the existing dissident groups or emerge as leader of yet another “stand alone” faction.
A source quoted in the Belfast Telegraph yesterday said: “We’ve had real concern about that area [Tyrone] recently – serious concern about leakage [from the mainstream IRA].”
The source said intelligence information suggested the former senior IRA figure planned to resume armed actions – that: “He has changed back to involvement.”
A republican who knows him said any return to violence would be with the intention of “wrecking” the peace process.
Late yesterday, none of the dissident groups had yet admitted being responsible for the murder of Constable Kerr.