A forensic voice analyst has been accused of carrying out a "flawed'' examination of secretly recorded conversations with three alleged members of an IRA group.
Professor Peter French was also accused of not carrying out an independent examination of the tapes without assistance from PSNI detectives.
The covert MI5 bugging operation allegedly captured 52-year-old Colin Duffy, Alex McCrory (58) and 51-year-old Henry Joseph Fitzsimons discussing a failed attempt to murder police officers in north Belfast over six years ago.
During a third day of cross-examination at the non-jury trial, defence counsel Barry McDonald QC for McCrory put it to prosecution voice analyst expert Professor Peter French that he had not carried out an independent examination of the tapes as he had first suggested.
Mr McDonald said it was clear from the records of a preliminary enquiry held in 2016, that Professor French already knew the names of the suspects, who were given the ciphers of 'M1, M2, M3' and had carried his work alongside a police transcript of recorded conversations from a car stop, telephone calls to an insurance company and a heavily bugged laneway in Lurgan.
Said the defence QC: "Why did you need the details of the three individuals?''
Profesor French replied: "Well, I didn't.''
Mr McDonald put it to the expert witness: "You were getting more help from the police...''
Professor French: "Well it didn't look like we requested that help. It is possible. I don't think so. I can't think why I asked for it. It would not have helped me.''
Mr McDonald put it to the witness that "you were getting a steer about who was M1, M2, and M3. How did you get that particular steer?''
The witness replied: "The names were written in the margins of the (police) transcript.''
The defence lawyer said in order for the witness to identify who M1, M2 and M3 were, the witness would have had to go through the transcripts to see who the police had attributed names on the voice recordings.
"You had to go looking for the transcript in order to see who they were, isn't that right?'' asked Mr McDonald.
Professor French replied: "Yes, in order to compare voices.''
Duffy, Fitzsimons and McCrory, whose addresses can't 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 of the two AK47 assault rifles and ammunition used in the 2013 attack.
The trio were allegedly covertly recorded and videod under an MI5 operation code-named 'Operation Idealistic" on December 6, 2013.
This was carried out in Demesne Park, Lurgan, owned and operated by Craigavon Council, the day after the Ardoyne gun attack when 14 high velocity shots were fired by two gunmen from AK47 assault rifles at a three vehicle police convoy as it travelled along the Crumlin Road.