Police Ombudsman Nuala O'Loan and the Chief Constable Sir Hugh Orde were due to be quizzed by the Policing Board today about collusion between Special Branch and loyalist killers.
Mrs O'Loan will brief the Board at Clarendon Dock today about her report which revealed that Special Branch gave protection to UVF informers in Mount Vernon, allowing them to carry out up to 15 murders.
Later the Chief Constable will take questions from board members about Mrs O'Loan's recommendations over how informers are handled.
It is expected to be a heated session with nationalist and unionist members sharply divided over the significance and consequences of the Ombudsman's bombshell report.
Nationalists have called for the resignation of Sir Ronnie Flanagan, who currently leads Her Majesty's Inspectorate of Constabulary (HMIC) but who was Chief Constable of the RUC while the Mount Vernon UVF gang were killing with impunity.
Sir Ronnie has responded by insisting he knew nothing about any collusion and has dismissed calls for him to resign from HMIC. He has also insisted that he co-operated fully with the Ombudsman's investigators.
However, unionist Policing Board members have described the report as one-sided and pointed out there are no hard facts which would lead to prosecutions.
Meanwhile, the father of murder victim Raymond McCord has said that senior officers who did not co-operate with the report should be stripped of their pensions in the light of the Ombudsman's findings.
According to reports today former Chief Constables, such as Sir Ronnie Flanagan, receive a pension payout of £431,405 and around £86,000 a year for life. Assistant Chief Constables receive £239,000 plus £47,500 a year for life.
The Ombudsman's report is also expected to be raised in the House of Commons during Prime Ministers questions.
A Sinn Fein delegation is also expected to call for action from the Irish government during a meeting later with Foreign Minister Dermott Ahern.
Mrs O'Loan's investigation, Operation Ballast, identified Mark Haddock as the key agent running the UVF gang in north Belfast's Mount Vernon estate.
He was paid at least £80,000 and protected from prosecution by Special Branch handlers who destroyed evidence, tipped him off and guided him through sham police interviews throughout a catalogue of murders stretching back to the early 1990s.