Investigations by Police Ombudsman Nuala O'Loan into circumstances surrounding the killings of Robert Hamill and Rosemary Nelson are complete and should be published later this year.
The Irish Times understands that Mrs O'Loan hopes to publish her findings before judicial inquiry hearings into both killings get under way, probably in October.
RUC collusion with loyalist paramilitaries has been alleged in both cases. Mr Hamill was kicked to death by a loyalist mob in Portadown in 1997. Armed RUC officers were stationed in a Land Rover near to the scene, but allegedly failed to intervene.
Ms Nelson, a solicitor, was murdered in a car-bomb attack outside her Lurgan home in March 1999.
Preliminary sittings of judicial inquiries into both cases, as recommended by Judge Peter Corey, have been held. Formal hearing are expected later this year.
Reliable sources have told The Irish Times Mrs O'Loan would like to publish her findings into the police handling of these cases before the judicial inquiry hearings begin.
Her office is also understood to be near to finalising investigations into other murders, including those of Sgt Joe Campbell, murdered in Cushendall, Co Antrim in 1990; and Raymond McCord, murdered in 1997.
These should also be published "before the end of this year".
Earlier this week Mrs O'Loan reported a fall in the number of complaints made against the PSNI. Her office recorded 2,885 complaints in the past year, a fall of 91 or 3 per cent on the previous 12 months.
Catholics and Protestants reported grievances in proportionate numbers, with 47 per cent describing themselves as Protestants and 37 per cent as Catholic.
Of the complaints made in the past 12 months, 1,590 were sufficiently important to require formal investigation.
Another 720 complainants agreed to use Mrs O'Loan's informal resolution process and a further 450 agreed to refer the matter back to the PSNI.
This year's figures show that 39 per cent of complaints involved allegations that officers failed to do their duty - an increase of 12 per cent in the past three years. The main cause of complaint - allegations of assault, intimidation or harassment - fell by 4 per cent last year, but still represented some 37 per cent of all complaints.
Mrs O'Loan also referred 149 cases to the Director of Public Prosecution, but recommended charges in just seven of these.
Her office also made a series of recommendations to the PSNI. These include the proposal that CS spray not be used to disperse crowds during street disorders and that a female officer be present where possible during searches where women are likely to be.
She also suggested that the police service consider a review of officer training relating to the application and execution of search warrants. The PSNI has already acted on this. She further suggested that the PSNI review the three-shot burst setting on the standard police handgun.
During the past 12 months the office closed 3,052 cases of complaint - in 43 per cent of cases it was felt that no further action was needed.