Martin Corey, 61, a suspected Republican dissident walked free from prison on Monday after successfully suing the British government over its power to keep evidence against him secret.
Corey's Belfast High Court victory ends his latest two-year imprisonment stint and delivers an embarrassing blow to a key provision in Britain's security policy in the North.
According to Fox News Corey originally received two life sentences for the IRA murder of two policemen in 1973. He served 19 years in prison and received parole on condition he would not become involved again in Republican activities.
For decades Britain has reserved the right to send any former IRA convict released on conditional license back to prison without a second trial if evidence suggested they had resumed their Republican ties.
Corey was pick up in April 2010 when the Northern Ireland Office (NIO) announced it had received confidential intelligence that he had become a member of the breakaway Continuity IRA group.
Corey's outraged lawyers demanded to see the evidence the NIO were operating on but were refused. They refused again at his parole board hearing last year.
In response Corey sued Britain, arguing its refusal to provide him with the evidence leveled against him breached the European Convention on Human Rights.
High Court Justice Seamus Treacy reportedly agreed this week, ordering Corey's immediate unconditional release and ruling that British authorities must disclose evidence to the accused if it is central to their imprisonment order.
The Northern Ireland Office offered no reaction to the order.
A Sinn Fein spokesperson welcomed the verdict on Monday and called for the release of two other IRA veterans currently imprisoned under the same power.
Sinn Fein politician Raymond McCartney told the press it was 'unacceptable that you can be imprisoned by the decision of a British secretary of state to revoke a license and place no evidence or proof before a court. The British government now need to end the pursuit of Martin Corey and drop any further attempts to intern him in the way they have.'
Corey was one of three IRA members convicted of murder for the February 27, 1973, killings of policemen William Wylie, 26, and Ronald MaCauley, 43.