A retired Garda superintendent said he had been concerned that a top RUC officer repeatedly used the same car to travel to the Republic in the months before he was killed in an IRA ambush.
Supt Bob Buchanan was murdered along with colleague Chief Supt Harry Breen near the Border after a meeting at Dundalk Garda station in March 1989.
Retired Garda supt Pat Tierney told the Smithwick Tribunal in Dublin that he met Mr Buchanan 12 times in both Northern Ireland and the Republic between early February and the day he died.
“I certainly was a little apprehensive,” Mr Tierney said. “I was conscious of the fact that he was coming quite often in the same car. It was a concern.”
The tribunal, established in 2005, is investigating allegations that Garda officers or a civilian working in the force colluded with the IRA in the murders.
Mr Buchanan made as many as two trips a week from Armagh to Dundalk Garda station, generally using the same car and arranging visits over an unsecured phone line, before he was ambushed and murdered along with a colleague, the Smithwick Tribunal was told.
The tribunal also heard Mr Buchanan had a relaxed and easy-going manner, and generally travelled in his own Northern-registered, red Vauxhall, parking it in the same car park in front of Dundalk Garda Station or on a nearby street.
This morning, Mr Tierney, who was a district officer in Dundalk at the time of the killings, said he had met Supt Buchanan "about 12 times times" between his arrival in Dundalk on February 2nd and the day of the murders on March 20th. Mr Tierney said nine of those meetings were south of the Border.
On the day of the ambush he said a number of phone calls were made between Dundalk Garda Station and a police station in Armagh but a "scrambler" for use on sensitive phone calls, when details of joint RUC-Garda operations might be discussed, would not have been used that day as the police station in Armagh did not have a compatible scrambling system.
Mr Tierney said he believed a conversation between his superior officer in Dundalk and Supt Buchanan and could have been electronically overheard.
Mr Tierney told Judge Peter Smithwick he had left on a patrol of Border crossings at about 11.30am with Insp Frank Murray, now deceased. He said Insp Murray had mentioned as they returned to Dundalk about 1.45pm that Supt Buchanan was travelling from Armagh with a colleague. Mr Tierney said he had "a snack" in the town and was back in the station shortly after 2.pm.
Later that afternoon, he took a call from a colleague in the RUC asking if the RUC officers had left as the RUC was hearing reports of an ambush near Meigh. Mr Tierney checked and said the officers had left. He told the judge he had feared the worst.
Mr Tierney, who was in charge of the Dundalk District office at the station, told the tribunal he had no evidence of any Garda or civilian collusion with the IRA.
Tribunal lawyer Dara Hayes said PSNI intelligence received more than 10 years after the killings claimed meetings between gardaí and the RUC were organised by a civilian administrator based at an unknown location in Ireland.
But Mr Tierney and another witness, former garda George Flynn who also worked in the district office at the time, said they had no knowledge of this.
Mr Breen and Mr Buchanan were two of the highest-ranking RUC officers killed in the Troubles.
They had travelled to Dundalk Garda Station in Co Louth to discuss a possible joint RUC/Garda police operation against smuggling and were returning to Northern Ireland when they were ambushed just north of the Border on the Edenappa Road.
Additional reporting PA
