An ex-soldier has claimed he was part of an undercover unit that carried out a shoot-to-kill policy against the IRA in the early years of the Troubles.
Simon Cursey details several incidents where he claims he was involved in the shooting of IRA men, but as this unit was operating outside the law and in secret there is little or no corroboration.
He claims in his book MRF Shadow Troop that their orders were to eliminate people and that course of action was sanctioned at high level.
"I killed people, but I've never had nightmares about it or loss of sleep," he said.
"Nothing, nothing like that. The people we are talking about were terrorists, they killed women and children.
"They were terrorists. They murdered people for nothing."
His allegations are so far unproven and run counter to the accepted direction the Army and intelligence services were working at the time.
Most analysts agree that rather than kill or jail IRA figures, they were trying to recruit them as informers.
Among the many facts that emerged during the trial of Army agent Brian Nelson more than 20 years ago was that the UDA 'intelligence officer' helped prevent a plot to kill Adams.
Nelson used files from another shadowy Army organisation, the Force Research Unit to help the UDA and its killing arm, the UFF, to target active republicans and also uninvolved nationalists.
Yet when it came to Adams it appears that Nelson's FRU handlers regarded this operation as a no-no.
The plan to assassinate the Sinn Fein President involved attaching a limpet mine to the car he was travelling in while raking the vehicle with gunfire.
However, the operation came to nothing thanks to Nelson's information passed back to FRU, although Adams escaped another UDA/UFF murder bid in central Belfast when the late John Gregg almost killed the then West Belfast MP.
Aside from the aborted Adams murder bid, Nelson is also thought to have stymied another assassination of a senior IRA figure in the Springhill area in 1987.
Because when Nelson told his FRU masters that the UDA/UFF were about to strike at the top republican the informer was told to find an alternative target. Instead Francisco Notorantonio, a pensioner and one-time IRA veteran from the 50s, was shot dead at his home nearby the original target.
On top of the Nelson scandal there is the controversy over Freddie Scappaticci, a top IRA spy hunter who himself was a highly-placed informant inside the movement.
It is clear the state agent was used by his handlers to 'remove' IRA personnel some of whom were falsely accused of being informers themselves.
From the state's viewpoint 'Stake Knife' was a brilliant operation given how high their agent was working inside IRA and how much insight he could provide on the organisation.
If you add up the other list of top level informers such as Denis Donaldson it is obvious that the Army, MI5 and RUC Special Branch all had voluminous information on the mechanics of the IRA's "armed struggle" as well as a vital grasp of key players especially those like Adams who from the early '80s onwards were trying to steer the movement towards democratic politics.