Garda efforts to investigate loyalist bombings in the Republic in the 1970s frequently hit a "brick wall" once their inquiries led them north of the Border, an Oireachtas sub-committee heard yesterday.
Retired Garda Sgt Owen Corrigan told the sub-committee on the Barron report on the bombing of Kay's Tavern in Dundalk in December 1975, that in one such instance, the initially helpful attitude of a senior RUC Criminal Investigation Department (CID) officer "changed completely".
This happened in February 1979 when Mr Corrigan and his superior officer, retired Chief Supt John Courtney, sought to meet an RUC constable in Belfast.
The constable was understood to have information about the theft of the car used in the bombing of Kay's Tavern, but the two gardaí were not permitted by the CID officer to meet him.
Mr Courtney agreed with this. Gardaí had "no authority" to go to the North to question individuals and were dependent upon RUC co-operation, he said.
However he had passed information regarding the suspected membership of RUC officers in the gang involved in many of the murders on to Garda security and intelligence, known as C3.
Both men agreed, in response to questioning from Senator Jim Walsh (FF), that it was their belief that there was collusion between British forces, the RUC and those involved in the bombing.
Garda Commissioner Noel Conroy said any files requested by Mr Justice Henry Barron had been given to him.