Police Ombudsman Nuala O'Loan has launched a top level probe into why cops failed to arrest Sinn Féin chief Gerry Adams over a double murder.
The launch of the inquiry came after the News of the World exclusively revealed in September how the West Belfast MP's fingerprints had been found on a stolen car linked to an IRA hit squad in October, 1971.
The link was uncovered after officers from the PSNI's cold case review team reinvestigated the murders of two RUC officers in north Belfast.
Detectives found that a forensic link to the murders of officers Cecil Cunningham, 46, and John Haslett, 21, was discovered in the late 1980s but that Mr Adams had never been questioned.
In recent months relatives of one of the murdered policemen contacted Mrs O'Loan's office for an explanation.
The inquiry comes at a crucial time, – just weeks after Sinn Féin agreed to support the PSNI —with efforts continuing to restore a devolved Assembly at Stormont by March 26 following Wednesday's elections.
An Ombudsman spokesman said last night: "We are looking at a complaint into how police handled and investigated the double murder."
Ironically, Mrs O'Loan's office had recently begun an investigation after a complaint from Mr Adams that the RUC's Special Branch failed to thwart a murder bid on him in 1984 – during which he was seriously injured – despite the fact that police officers had been tipped off by a UDA informer.
Mrs O'Loan is also investigating whether police covered up the activities of IRA superspy Freddie Scappaticci.
Last week we revealed, under the Freedom of Information Act, how the Stevens Inquiry has arrested and quizzed the agent known as Stakeknife about a total of 16 murders.
In October, 1971, Constables Cunningham and Haslett were in plain clothes in an unmarked car at Woodvale Road in north Belfast.
They were watching a bank and post office after a spate of robberies in the area when IRA gunmen driving a green Ford Cortina raked their car with bullets.Constable Cunningham, married with a nine-year-old son, was one of five Co Fermanagh brothers who joined the police to follow in their father's footsteps.
Constable Haslett was a single man from East Belfast and had been in the RUC for just over a year.
Within hours of the murders, police found the Cortina in the Ardoyne area of Belfast. Cops never established if the burning car was the gunmen's or one of two used by the gang.
But modern DNA techniques used to analyse a set of fingerprints on the car identified them as belonging to Mr Adams. The Cortina at the centre of the case had been stolen some months before the murders, resprayed green and fitted with false number plates.
An internal report into the double murder review revealed that despite his fingerprints being linked to the case almost 20 years ago Adams was never interviewed about this.
When quizzed by reporters about the murder controversy, Mr Adams said: "I don't want to comment. I don't want to feed it. They are investigating something I know nothing about."
Following our story, PSNI Chief Constable Sir Hugh Orde told the Policing Board in a private session that the Sinn Féin leader was under investigation.
The Sinn Féin president has always denied being involved in the IRA despite widespread claims to the contrary from fellow republicans and security force members.
