Three alleged British agents operating in the IRA are being investigated by Nuala O'Loan, the police ombudsman, as part of her inquiry into collusion between the terrorist group and the security forces.
The roles of Freddie Scappaticci, Kevin Fulton and an IRA intelligence officer known as "the Hawk" are being examined by O'Loan. She is acting on complaints that several agents in the IRA were protected from prosecution by their police handlers to avoid blowing their cover.
The allegations are similar to those O'Loan upheld in her recent Ballast Report on the handling of Mark Haddock, an agent within the UVF who was involved in several murders.
The most recent complaint to O'Loan was made by Irene Dignan, whose son John was one of three Armagh men kidnapped and murdered by the IRA in July, 1992. The other two were Gregory Burns and Aidan Stars.
The IRA said the three were killed because of their involvement in the murder of Margaret Perry, Burns's girlfriend, who discovered that Burns was a police informer.
The IRA believed that the police recruited Dignan and Stars as informers while questioning them about Perry's death.
Two other linked cases being examined by O'Loan are the murder of Joseph Fenton, a Belfast estate agent killed by the IRA's internal-security section in 1989, and the abduction of Sandy Lynch, a police agent within the IRA. Lynch was held in the same house as Fenton, but was rescued by the army in an elaborate sting operation that netted Danny Morrison, then Sinn Féin head of publicity. Scappaticci, an army agent, is said to have left the house minutes before the army raided it and arrested Morrison.
Lynch gave a misleading description of Scappaticci and the ombudsman will now look at whether he was told to do this by his police handlers in order to protect the most valuable agent the security services had in the IRA.
Lynch may himself have been protected from charges of shooting and wounding a man accused of being an informer in Downpatrick.
Fenton's handler, a retired RUC Special Branch officer formerly based at Woodburn Police Station, was arrested and had his house raided by the ombudsman's investigators last week. He had earlier visited the ombudsman's office with allegations about Fenton's death and had given them a number of papers but withdrew his co-operation after an argument.
He had also contacted Tom Travers, a former magistrate, about the death of his daughter Mary, who was shot by the IRA as she left mass with her father in south Belfast.
Travers, who was thought to be the gunmen's intended target, recognised one of the killers but his evidence was thrown out in court.
The retired Special Branch officer is understood to have told Travers that evidence which could have identified the killer as a police agent was destroyed by another informant within the IRA on the instructions of Special Branch. This is believed to have been the murder weapon, which was in control of Special Branch for 12 hours but never recovered and given to CID.
The ombudsman is also looking at the case of Patsy Gillespie, a worker on an army base, who was forced to drive a bomb to a checkpoint in 1990 and blown up along with five soldiers.
The Smithwick tribunal in Dublin is already investigating allegations that Scappaticci, a senior figure in the IRA's internal-security department, was "handling" a garda for IRA intelligence while being himself controlled by British military intelligence. The garda has been accused of feeding information to the IRA on the movements of Harry Breen and Bob Buchanan, two RUC officers shot dead in an ambush in 1989 as they drove back to Northern Ireland after an exchange of intelligence at Dundalk garda station.
Justice Smithwick has not yet established if the garda, a detective, did help the IRA or if the RUC officers' movements were being monitored in another way. Similarly, O'Loan has stressed that she is not saying whether anyone was or was not an agent, simply investigating complaints.