IN 2003 west Belfast man Freddie Scappaticci was publicly named as the highest ranking British agent within the IRA.
Details of the mole known as Stakeknife caused huge embarrassment for the republican movement, who at the time denied the existence of IRA/state collusion.
A once trusted friend of Gerry Adams, Scappaticci at first tried to ride out the allegations and gave television and newspaper interviews in which he denied involvement. However, he fled Northern Ireland soon afterwards.
The grandson of an Italian immigrant, Scappaticci's IRA 'career' had seen him rise through the ranks to become its northern head of internal security - the infamous 'nutting squad'.
In 1971 he had been interned in Long Kesh, where he is said to have become close to the Sinn Féin leader who was also interned at the time.
His powerful role meant he vetted every IRA member and hunted down and interrogated all suspected informers.
In 1978 he suffered a vicious beating following an argument with a senior Belfast IRA figure and it is claimed that, hungry for revenge, Scappaticci then decided to become a British army informer.
He gave an interview with ITN's Cook Report in the 1980s during which he revealed his clandestine activities but the recording only came to light after he was unmasked in 2003.
In the early 1990s, Scappaticci scaled down his involvement in the IRA, citing a heart condition.
Sources say that as suspicion around him grew he was sidelined and the internal security unit 'stood down'.
It is now believed that the agent known as Stakeknife either directly carried out, ordered or oversaw up to 40 murders, 24 of which are now to be subject to a new investigation on the recommendation of the head of the PPS.
