It is reported that Gardai are now satisfied that a faction of the Real IRA was behind the murder of former Sinn Fein administrator-turned-spy Denis Donaldson in Glenties.
Officers believe that he was shot dead by Derry-based Real IRA dissidents in a bid to create problems for the mainstream Provisional republican movement, which was initially blamed for the attack.
According to today's Irish Independent Gardai are following a number of lines of inquiry that have emerged in recent weeks.
The paper says a senior officer admitted that they did not know yet if these could lead to a breakthrough in the case.
56 year-old Donaldson was shot four times in his remote cottage at Cloghercor, Glenties on April 4, 2007.
Gardai said the investigation into his death remained 'live' and a dedicated team of detectives was working full-time on solving the case.
They are reported to now believe that associates of a major Real IRA figure in Derry city organised and carried out the shooting.
The inquest into Donaldson's death was again adjourned in Letterkenny last week at the request of the gardai, who said "technical" avenues of investigation were being pursued.