The British government will next week seek a gagging order banning a Belfast court from identifying a leading dissident republican as a top security-force agent.
Earlier this year Paddy Murray (44) publicly rubbished speculation that he had been taken into protective custody by police after coming under suspicion of being an agent.
In recent years he has been a prominent spokesman for dissident republicans, arranging a series of controversial band parades in Ballymena, Co Antrim.
However, the government is taking the highly unusual step of seeking a Public Interest Immunity Certificate to prevent Murray from being identified as one of its top agents.
Murray first came under suspicion after police uncovered a Real IRA bomb factory in Ballymena in February 2005.
Four men and a woman were charged with possession of incendiary devices after a house on the Fisherwick estate was raided. Murray was arrested but later released without charge.
Earlier this year the Police Ombudsman was asked to investigate a complaint that police had protected Murray from being charged in connection with the bomb factory. It was claimed that police deliberately withheld evidence that Murray had supplied bomb timers to the Real IRA gang days before a planned attack and that his DNA was found on two incendiary devices recovered during the raid.
Last month when Murray appeared in court on separate kidnapping and assault charges he was accompanied by two police officers.
Despite being freed on bail he openly walked back into police custody.
A private court hearing will take place in Belfast on Tuesday during which a judge will be asked to grant a certificate banning any details of Murray's alleged role as a security-force agent being revealed in the forthcoming Real IRA bomb trial.
In the past such certificates have only been granted in high-profile cases where it is claimed that Britain's national security would be put in danger if evidence is disclosed in open court. They can only be issued if a British government minister can convince a judge that national security would be put at risk.
In the past they have been used to prevent the identification of key informers, police officers and soldiers involved in some of the most controversial killings of the Troubles.
In 2000 the then defence minister, Geoff Hoon, issued certificates to prevent security-force agents and their military handlers from being identified at the Bloody Sunday Tribunal.
