An illegal mobile phone, charger and notebooks were seized in a jail cell search by detectives investigating the intimidation of prosecution witnesses in the trial of a Co Armagh man for the murder of a garda.
Aaron Brady (29) will be sentenced to the mandatory term of 40 years in jail for the capital murder of Detective Garda Adrian Donohoe at Dublin's Central Criminal Court on October 14.
The target of the search was a notorious north inner city criminal aligned to the Kinahan cartel.
Officers from the Republic's National Bureau of Criminal Investigation (NBCI) were backed up by the Operational Support Group (OSG) in Mountjoy Prison in the search operation last Friday morning.
"Key evidence was seized and this may prove to be very useful in the ongoing witness intimidation investigation. That trial was blighted by witness intimidation," a senior source said.
"The phone and the notepads will now be analysed and there are plans for more targeted searches in the weeks ahead," the source added.
Crossmaglen man Brady was convicted after a lengthy trial and, even before it ended, the NBCI had begun a detailed probe into the intimidation of a number of witnesses.
In mid-July detectives searched the Mountjoy cell of a violent north Dublin criminal with over 120 convictions who is currently serving a lengthy sentence for aggravated burglary.
No mobile phone was located but a piece of paper with several phone numbers scrawled on it was seized. Gardai are investigating if the intimidation of certain witnesses was "outsourced".
Properties linked to Traveller criminals in Finglas, Blanchardstown, Balbriggan and Coolock were also searched as part of the same intimidation probe.
There have been no arrests so far in the investigation. The latest target is serving a six-and-a-half year sentence after pleading guilty to possessing two loaded handguns as well as almost €70,000 worth of cocaine in September 2010.
He was previously arrested by detectives investigating another murder in April of that year and spent over six years on the run in the UK and Spain before being arrested in Spain in August 2017 on foot of a European Arrest Warrant.
Last Friday was the fourth time he was caught with an illegal mobile phone while serving his sentence in Mountjoy Prison.
In January of last year he was given a two-month suspended sentence after Dublin District Court heard he used an illegal mobile phone to call home.
In the second incident prison officers also found a charger and Sim card, the court was told.
A campaign of intimidation against key prosecution witnesses was a constant feature throughout the Donohoe murder trial.
Before he was even arrested for murder Brady was identifying people who could have potentially incriminating evidence against him.
Serious concerns were raised throughout the trial about witness interference, but the jury never knew about this.
Seven people were expected to give evidence about admissions Brady had made, but ultimately only two appeared before the court.
One senior officer described it as the "dirtiest" trial he had ever come across.
In some cases potential witnesses who had overstayed their visas in the US were threatened that their residency status would be exposed.
The most serious example of intimidation came to light in May when the statement of a key prosecution witness, which was video recorded, was leaked on social media. It came at a critical time as witnesses living in the US were due to start giving evidence.