The Smithwick Tribunal has heard a claim that Northern Ireland Deputy First Minister Martin McGuinness was involved in authorising the IRA murder of two RUC officers in March 1989.
The claim, which Sinn Fein denies, was made by former British intelligence officer Ian Hurst - also known as Martin Ingram.
The two RUC officers were ambushed as they returned from a meeting in Dundalk Garda Station, with claims that there was garda collusion in the attack.
Mr Hurst gave evidence to the tribunal in private session last week, and his evidence has been read into the record today with some slight redactions.
Mr Hurst claimed the operation to kill the two RUC officers would have needed political cover, adding the plan was to get paperwork they were believed to be carrying, and then kill them. He said he believes the authorisation came from Northern Command, of which he clamned Martin Mc Guinness was officer in command at the time.
A Sinn Fein spokesperson has rejected the allegations, saying they were "more lies from an individual with a highly dubious track record"
The tribunal was established in 2005 to investigate allegations of Garda collusion in the murders of RUC Chief Superintendent Harry Breen and RUC Superintendent Robert Buchanan.