Former deputy chief constable Blair Wallace told the inquiry that in the early 1980s, an intelligence source passed information about IRA activities in North Louth, but with the “caveat” that it “was not worth acting upon if it was given to Dundalk.”
“The belief from the source was that Dundalk would immediately compromise the intelligence,” Mr Wallace said.
The tribunal is looking at allegations that a leak from Dundalk garda station led to the murder of two RUC officers, chief superintendent Harry Breen and superintendent Bob Buchanan, as they returned from a meeting in the border town.
Mr Wallace said that as a result of the “caveat”, the RUC contacted Garda HQ, and asked that a taskforce from headquarters should investigate the intelligence reports.
“I am quite sure that somebody in command would have said, why are we bypassing Dundalk,” he said.
He said that no individual within Dundalk garda station was named by the intelligence source.
Mr Wallace also said that cross-border cooperation did not work as envisioned in the 1985 Anglo-Irish Agreement, and intelligence reports that there was a Garda mole had not been shared.
The tribunal had previously been told of three Garda intelligence reports in the wake of the murders of Mr Breen and Mr Buchanan stating that there was a contact within the force passing information to the IRA.
And Mr Wallace outlined several steps an investigator could take to assess whether an officer was providing information to terrorists, including examination of his bank statements and property portfolios, whether he went missing unaccountably while on duty, and whether intelligence he supplied turned out to be “a damp squib”.
The former deputy chief constable also said that statements from the Garda commissioner and RUC chief constable made within 24 hours of the double murder, dismissing the possiblility of a “mole”, were “premature”.
“All avenues of inquiry should have been kept open,” he said.
“My view was it was closing down one avenue of investigation.”
Mr Wallace said he did not have any “direct evidence” against any particular garda officer in Dundalk. He said that if rumours “took on a dimension that they had credence, the should be investigated”, and he would prefer an investigation which turned out to be a damp squib than to “leave the rumour festering.”
The tribunal resumes next Tuesday.