Fire-starter Mark Harte - jailed over a €1.8 million arson attack linked to the drug trafficker 'Mr Big' - was moved from the Dublin jail to maximum security Portlaoise Prison on Thursday night.
Sunday World revealed last week how another female officer in the prison was threatened after she learned of Harte's alleged 'inappropriate relationship' with her colleague.
This innocent officer was later provided with personal security advice by gardaí who viewed the threats against her as 'serious.'
We could not name Harte (29) previously as he was facing trial on separate serious charges including aggravated burglary, carrying a firearm with intent and making off without paying.
However, these charges were dropped on Thursday after a jury at Dublin Circuit Criminal Court was directed by a judge to return a not guilty verdict on each one.
This means that Harte can now be identified in connection with the ongoing probes into the 'inappropriate relationship' and threats against the innocent prison officer's life.
The Irish Prison Service was expecting to interview the officer with whom Harte was 'inappropriately involved' earlier this week.
But she resigned her position before Prison Service officials had the chance to interview her.
Gardaí are now likely to seek to speak with her - although there is no suggestion she has involved herself in any criminality.
The Irish Prison Service's investigations are now instead focussed on Harte and the discovery of a phone in his cell in the Dublin Prison - as well as his prison issue laptop on which pornography was discovered.
The phone was handed over to Gardaí and is now being examined to see if it was used to facilitate the threats made against the innocent officer.
A laptop used by Harte for college work in the prison has now also been examined.
Sources this week confirmed that pornography has been recovered on the device.
Harte has already been subjected to P19 disciplinary proceedings for possession of a contraband mobile phone in his cell and the discovery of the pornography.
His transfer to Portlaoise Prison on Thursday night is also directly linked to the ongoing probes into the threats against the innocent officer.
Harte was jailed for six-and-a-half-years in 2019 for burning down a Flyefit gym in north Dublin, which resulted in almost €2 million of damage and lost earnings.
Harte said he carried out the arson attack in July 2016 for a criminal gang he had built up a drug debt to because of his cocaine use.
Sources later said the attack was ordered by criminals linked to the Dublin drug trafficker known as 'Mr Big'.
'Mr Big' is one of the most feared gang bosses in the capital and the State.
The gang boss has been involved in the higher levels of organised crime for more than 15 years.
Based in Coolock, he is believed by Gardaí to have orchestrated the murder of Real IRA terror boss Alan Ryan.
Gardaí also believe he runs a drug-trafficking network on an international scale.
Details of the arson attack carried out by Harte were given at his sentencing hearing at Dublin Circuit Criminal Court in June of 2019.
The court heard a car was driven through the front doors of the Flyefit gym and stopped at the security turnstiles inside the doors.
Harte had left the car before this happened and was holding a container.
CCTV footage played to the court showed a bright flash of light before the car went up on fire.
Judge Pauline Codd said the footage was chilling and sinister.
Keith Spencer BL, defending, said the crime was completely out of character and his client deeply regretted the harm he caused.
He said his client made sure there were no individuals in the vicinity of the car at the time.
Counsel said Harte went to door of the gym to make sure there was nobody there and then gave a sign to the driver of the car.
Det Garda Neill Plunkett said he believed that Harte was saying 'the coast is clear' before they drove the car in.
Judge Codd said that two employees were in the building and had to leave. She said they had a frightening experience.
Harte was linked to the scene from DNA found on white latex gloves found nearby.
A neighbour told Gardaí about a suspicious car that had been parked in the area and provided them with a photograph taken on his mobile phone.
This car was linked to Harte and he was arrested at his home on Collins Avenue in Donnycarney.
He pleaded guilty to arson at Flyefit gym, Coolock on July 25, 2016.
The court heard that the owners of the building, Irish Life, set the costs of damage repairs at €316,000 and the loss of rent at €85,000.
Flyefit put the cost of damage to equipment at €915,000 and the loss of business at €569,000.
Judge Codd set a headline sentence of 11 years but reduced this to nine years after noting evidence that Harte was petrified because of a drug debt and was worried for the safety of his family.
She also noted he was assessed as being at a low risk of re-offending. She said he had made good progress in drug treatment and came from a good family
An IPS spokesman declined to comment on the ongoing investigations into the alleged threats and 'inappropriate relationship' when contacted by the
A spokesperson said: "The Irish Prison Service does not comment on ongoing investigations."
However, it's understood senior prison management are "very concerned" by what has allegedly occurred in the Dublin jail.
The innocent female prison officer who was the subject of the threats is also being provided with ongoing support by the IPS in the wake of the threats.