Lawyers for the PSNI blocked a bid by the Garda commissioner’s legal team at the Smithwick tribunal to find out if radio transmissions between IRA units were monitored on the day two senior PSNI officers were killed in an ambush as they returned from a meeting in Dundalk garda station.
The tribunal is looking at claims that a garda tip-off allowed the IRA to set up the ambush in which chief superintendent Harry Breen and superintendent Bob Buchanan died on 20 May 1989.
A retired RUC officer previously told the tribunal that he was informed by a senior RUC Special Branch officer radio transmissions were detected from around midday on the day of the murders.
But when Michael Durack SC asked another former RUC Special Branch officer, identified as Witness 29, about the transmissions, PSNI barrister Mark Robinson BL objected that it would reveal “operational details”.
The witness served as a chief inspector in the Special Branch at the time of the murders, in a section called the Task and Co-ordinating Group (TCG) which co-ordinated “covert resources”. He said monitoring communications would not have been the role of the TCG.
Mr Durack said if the evidence of the earlier witness was accepted, then “somebody must have been monitoring”.
Following the intervention, tribunal chairman asked Mr Durack if he would like to continue his cross-examination in closed session with members of the press and public excluded.
“I’ll leave it there rather than cause any further panic,” Mr Durack said.
Earlier, the legal teams for the PSNI and Garda commissioner clashed over the accuracy of an intelligence intelligence presented to the tribunal which says a detective sergeant was “helping out the provisional IRA”.
The summary said that retired detective sergeant Owen Corrigan was “keeping both the boys and the organisation well informed and he lets the boys know what the Security Forces are doing in the North when he can.”
Mr Corrigan has described allegations that he colluded with the IRA as “a monstrous lie”.
Barrister Demot McGuinness SC for the garda commissioner said that he would dispute the accuracy of the summary, which was agreed between the PSNI and the tribunal’s legal team.
The tribunal later rose to allow lawyers for the PSNI to seek instructions about a letter sent to the Garda commissioner about the intelligence report.
On behalf of the PSNI, Mr Robinson later confirmed that the summary shown at the tribunal did name Mr Corrigan, and that his name was given accurately, as were his rank, and garda station.
Mr McGuinness said he was reserving the commissioner’s position in every respect.
The tribunal also heard from the former deputy head of the RUC Special Branch, identified at the tribunal as Witness 24, worked in RUC headquarters as a superintendent in the 1980s, first in charge of the IRA “desk”, and then as head of the E3 section, which contained “desks” covering republicans, loyalists and communists.
The witness said he could not recall seeing a Special Branch intelligence report on Mr Corrigan.
He said that if such a report was made, he would expect the information to be passed on to senior gardai.
He said that he never saw a Special Branch file on Owen Corrigan, or on rogue gardai suspected of having dealings with the IRA.
Asked about the evidence from another witness that Special Branch officer Frank Murray said there was increased radio traffic along the border from midday on the day of the ambush, Witness 24 said “If he said that I have no reason to doubt it”.
Mr Breen and Mr Buchanan did not leave Newry for Dundalk until after 1pm on the day they were killed.