A major MI5 surveillance operation against three Co Armagh republicans used methods never publicly revealed before.
New details of the sting have emerged after the case against the men collapsed this week.
Brothers Paul and Damien Duffy, along with their cousin Shane Duffy, were acquitted of all paramilitary related charges at a Belfast court on Thursday.
The charges, which the men had denied, included conspiracy to murder police and prison officers.
The acquittal could now have implications for other cases where security force surveillance is being relied on as evidence.
The men’s solicitor Niall Murphy, of KRW Law, has called on the Public Prosecution Service to carry out an “urgent review” of similar cases.
The Duffys' case collapsed during a disclosure hearing when prosecution solicitors offered no further evidence against the men after a judge ordered them to hand over details of a vehicle tracking device.
The PPS argued that some information regarding the device should not be shared with the defendants, although it could be given to an expert engaged by their lawyers under a confidentiality agreement.
"Whilst the judge accepted the prosecution submissions in relation to the sensitivity of the information he ruled that a fair trial could only be achieved if disclosure was made both to the defence expert and the defendants personally," it said.
"The prosecution were unable to comply with the judge's order and in those circumstances could not rely upon the tracking evidence."
"Having reviewed the remaining evidence, it was decided that the test for prosecution was no longer met."
Defence lawyers did, however, receive other information about the surveillance operation which revealed it was of a type and detail never seen before.
The MI5-led operation, which lasted almost three years, involved the use of audio surveillance and tracking devices fitted to several vehicles.
It is believed a helicopter was also used to monitor the men.
Exhibits presented to defence solicitors included detailed maps and graphics highlighting the movement of cars containing the men.
Information from bugs planted in the cars was ‘overlaid’ with GPS co-ordinates from trackers, meaning surveillance teams could identify the exact time and location comments were made.
Video footage, at times reconstructed by the PSNI, was also added to the computerised exhibits to recreate what could be seen from the vehicles at the location and times conversations were held.
The extraordinary operation was supplemented by ‘aerial platform footage”, which may have involved the use of drones, or ‘heletele’ footage filmed from a PSNI chopper.
At times this aerial footage was also inlaid on the exhibit to show where the car was in real time.
The Irish News revealed yesterday that the huge surveillance operation, which cost millions of pounds, involved 44 MI5 officers, who are known as ‘Pins’.
In addition 35 PSNI officers, known as ‘Oscars’, were involved.
Mr Murphy said “an exhibit of this nature has never been seen before in our courts”.
“The three accused were subject to the most sophisticated and intensive methods of surveillance ever seen in this jurisdiction, involving vehicle tracker devices planted in several cars, helicopter surveillance on many dates, complemented by on the ground covert undercover PSNI and Security Service operatives.”
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http://www.irishnews.com/news/2015/10/24/news/mi5-surveillance-most-sophisticated-ever-seen--303792/