The judge heading a public inquiry into the murder of two RUC officers vowed today to investigate whether gardaí tipped off their IRA killers or turned a blind eye to information prior to the attack.
Chief Supt Harry Breen and Supt Robert Buchanan were killed in an IRA ambush near the Border between Louth and south Armagh on March 20th, 1989, as they returned from an informal meeting with senior gardaí in Dundalk.
It has been claimed that the IRA were tipped off about the route the men had planned to take by a member of the Garda.
At the opening of the tribunal in Dublin, Judge Peter Smithwick said he would investigate all of the allegations of collusion.
"While it generally means the commission of an act, I am of the view that it should also be considered in terms of an omission or failure to act.
"I intend to examine whether anybody turned a blind eye to it, or pretended ignorance or unawareness of something one ought morally, legally or officially oppose."
He said he wanted to express his deepest sympathy to members of the Breen and Buchanan families on their loss.
"I can well understand that the holding of this inquiry may bring back unhappy memories for them. I wish to assure the families that the tribunal will, while having a duty and obligation in the matter, be mindful of their sensitivities."
Judge Smithwick said the tribunal would have full powers to compel the attendance of witnesses and would function impartially and independently.
The setting up of the tribunal was prompted by the Canadian judge Peter Cory, who investigated the murder of the two RUC men.
After outlining this material from Judge Cory's report, Judge Smithwick said he had the power to grant legal representation to individuals with a direct interest in the tribunal's proceedings.
In the most dramatic moment of the opening day, barrister Jim O'Callaghan made an application for legal representation for Owen Corrigan, a retired detective sergeant who worked in the Border region for more than 30 years before retiring in 1991.
He said the former garda could be of no assistance to the tribunal but had been dragged into the matter by Democratic Unionist Party member Jeffrey Donaldson.
The tribunal heard that Mr Donaldson, then a member of the Ulster Unionist Party, had used his parliamentary privilege in the House of Commons in 2000 to suggest that Det Sgt Corrigan passed on information to the IRA about the meeting of the RUC officers with Irish police in Dundalk.
"That statement by Jeffrey Donaldson was a monstrous lie. It was false and my client wishes to establish the falsehood of it," said Mr O'Callaghan.
Det Sgt Corrigan appeared before an Irish parliamentary committee last month to testify about his role in the investigation of the sectarian murder of Seamus Ludlow, a Dundalk forestry worker, in 1976.
He expressed his frustration at the failure of his superiors to give him permission to travel to the North to follow up information about the suspected loyalist killers.