Jeffrey Donaldson testifying at Smithwick Tribunal
Jeffrey Donaldson has told a tribunal a former British agent inside the IRA told him a Garda sergeant in Dundalk had passed information to the IRA.
The DUP MP was testifying at the Smithwick Tribunal in Dublin.
The tribunal is investigating alleged collusion in the deaths of two senior RUC officers in 1989.
Chief Supt Harry Breen and Supt Bob Buchanan were shot dead by the IRA in south Armagh as they returned from a meeting at Dundalk Garda Station.
Mr Donaldson said Kevin Fulton was his only source that led to his naming of retired Detective Sergeant Owen Corrigan, under parliamentary privilege in the House of Commons in April 2000, as being a "rogue garda".
Mr Corrigan denies all allegations of collusion.
Mr Donaldson told the tribunal that victims campaigner William Frazer introduced him to Mr Fulton.
"After the the publication of Toby Harnden's book 'Bandit Country' I met with William Frazer who said he would introduce me to someone who could provide extra information," he said.
Mr Donaldson said he met with Newry man Mr Fulton - whose real name is Peter Keely - twice before making his statement in the House of Commons in April 2000.
"I wanted to be sure Kevin Fulton was who he said he was," he said. "I sought to confirm this from a senior member of the security forces, who did."'Bait for inquiry'
Mr Donaldson declined to publicly name the senior security forces person he had met with but wrote the person's name on a piece of paper for the tribunal chairman, Judge Peter Smithwick.
Mr Donaldson denied that he used Owen Corrigan as 'bait' for the setting up of an inquiry.
"By naming Owen Corrigan I was demonstrating that there was evidence that was important and relevant that strengthened the case for holding a public inquiry, I do not regret it."
"I used evidence that was given to me but 'getting at an individual' was not my motivation, getting to the truth was."
He agreed with Jim O'Callaghan, counsel for Mr Corrigan, that if the tribunal did not conclude that Mr Corrigan was an IRA mole he would be right to feel aggrieved.
But Mr Donaldson disagreed that there was "no necessity" to name Mr Corrigan.
"It's a matter of judgement, I have a mandate" he said, " The judgement I make as a politician is to do what I believe is in the public interest."
Mr Donaldson also spoke of his "high regard" for the Garda.
"I have never sought to blacken the name of the force because of the action of a few individuals," he said.
"My concern was about the action of individual members of the Garda, who may have through their acts of omission or commission assisted the IRA in their campaign."Cousins murdered
He also spoke of why he had taken what he described as a "particular interest" in the murders of the RUC officers.
"They were the two most senior RUC officers murdered by the IRA, Mr Buchanan's family lived in my constituency, I lost two cousins, both were in the RUC and murdered by the IRA in south Armagh."
Mr Donaldson said he was out of the country during the funerals but spoke of "press speculation and discussions in political terms" following the murders.
"Over a period of time the public's interest moved on, but suspicions and concerns, for a number of us, was still there," he said.
The tribunal continues.