A forensic voice analyst has denied misinterpreting the results of tests on secretly recorded conversations of three alleged members of the dissident IRA.
The covert MI5 bugging operation allegedly captured 52-year-old Colin Duffy, Henry Joseph Fitzsimons (51) and Alex McCrory (58) discussing a failed attempt to murder police officers in north Belfast six years ago.
A convoy of three police vehicles came under attack from AK47 assault rifles as it drove along the Crumlin Road on December 5, 2013.
Professor Peter French, who has more than 35 years of experience in the field of voice analysis, spent a second day in the witness box yesterday at the trial of the three men, being cross-examined about the results of his tests.
The chairman of the Forensic Speech Laboratory examined voice recordings from a car, calls to an insurance company and audio from secret listening devices planted by MI5 in a laneway in Lurgan.
Eilis McDermott QC, defence counsel for Fitzsimons, put it to Professor French that another expert in the field of linguistic analysis had disputed his findings.
She said the opinion of the defence expert witness was that Fitzsimons spoke in the dialect of "Lagan Valley English" and not "standard British English", as Prof French had used to compare voice analysis.
But Prof French disputed the expert's opinion, saying: "It is a fundamental misunderstanding of the whole process.''
Asked if he had been requested to give a written response to the expert's counter report on the voice analysis, he replied: "No, I have not. If I had (have been asked), I would have (given a written response)."
During cross-examination by Duffy's defence counsel Mark Mulholland QC, Prof French was asked why he had not made a written note of a meeting he had with PSNI detectives in January 2014, when he was approached about conducting an analysis of the tape recordings.
It was put to the witness that the Public Prosecution Service had issued a code of practice to defence experts about such meetings between police and potential expert witnesses.
Prof French replied: "I didn't take any notes because at that stage I was not allocated as the expert.''
He added that the purpose of the meeting was to assess the voice recording material, how long it would take to analyse and provide a written estimate of how much the work would cost.
Duffy, Fitzsimons and McCrory, whose addresses cannot be given at this time, deny preparing and directing terrorism and membership or professing to be members of the IRA.
Fitzsimons and McCrory are also charged with and deny attempting to murder police in the convoy and possessing the two AK47 assault rifles and ammunition used in the attack.
The trio were allegedly covertly recorded and filmed under an MI5 operation code-named Operation Idealistic on December 6, 2013.
This was carried out in Demesne Park in Lurgan, owned and operated by Craigavon Council, the day after the Ardoyne gun attack, when 14 high-velocity shots were fired by two gunmen.