Senior RUC officers are believed to have been implicated in a report on an investigation into a series of controversial murders in the North, it emerged tonight.
Their names will be passed to Chief Constable Sir Hugh Orde and Secretary of State Peter Hain when details are published on Monday.
It follows a massive probe by the Police Ombudsman Nuala O'Loan into how a gang of north Belfast loyalist paramilitaries, some working as Special Branch informants, were allegedly allowed to murder at will.
One of the victims was Catholic taxi driver Sharon McKenna, 27, who was shot in the back 14 years ago tomorrow, while she cooked dinner for a Protestant pensioner friend.
The report will likely be the most complex and devastating ever published on the intelligence work of the RUC, and will claim shocking levels of collusion between detectives and a gang of UVF men based at that time in the Mount Vernon area of north Belfast.
Downing Street has already been warned that the fall-out over Mrs O'Loan's findings will be enormous and deeply, deeply embarrassing for authorities in the North.
Several former policemen, including a number who worked at a senior level within the RUC before the Police Service of Northern Ireland took over have been linked in the report. Their names and those of the agents who worked for them will be withheld in the published findings, but the Chief Constable and Mr Hain will give the identities in more detailed reports.
Files are with the Crown Prosecution Service which will consider if criminal charges are to be pursued.
The Ombudsman's report centres on a Special Branch agent Mark Haddock, who was shot and wounded in an attempt on his life by former associates last year.
Mrs O'Loan's spokesman tonight refused to make any comment in advance of Monday's publication. The allegations of collusion - so far unchallenged - are linked to a series of murders, and attempted murders, which run into double figures going as far back as the early 1990s.
The Ombudsman's investigation which began in May 2002 followed the murder in November 1997 of an ex-RAF man Raymond McCord 22, who was beaten to death by the UVF. It was ordered by a high-level informer within Special Branch, the same man who was allegedly involved in the killing of the woman taxi driver in January 1993.
Today marks the 14th anniversary of the shooting of Ms McKenna from Newtownabbey, who was gunned down when she answered a knock on the front door by a man who demanded her car keys.
Nobody has ever been charged in connection with the McCord and McKenna murders, but politicians on all sides will expect a quick response from the Crown Prosecution Service after Monday's findings are revealed in Belfast.
The McKenna killing is one of 3,268 unsolved murders being examined by a special investigations unit.