The images highlight yet again how illegal phones remain a scourge within the prison, notwithstanding recent and massive seizures of contraband in the jail.
The latest prison photographs have emerged just a week after the Sunday World published pictures of Kinahan cartel gunman Trevor Byrne celebrating his 40th birthday alongside cartel associates in the same prison.
We also published video showing the caged gunman laughing about shootings with a Limerick associate.
Those images and video of Byrne were also recorded and circulated from inside the prison via contraband mobile phone.
Barry Doyle shot dead Limerick rugby captain Shane Geoghegan 13 years ago on Tuesday last.
Previously, Doyle was one of a number of Kinahan cartel inmates, including Freddie Thompson and Jonathan Keogh, who were moved from Mountjoy to Portlaoise Prison in March 2018 due to the level of control the cartel were exerting in the jail.
Thompson and Keogh are serving life for the murders of Daithi Douglas and Gareth Hutch respectively.
Doyle subsequently petitioned to be moved back to Dublin, claiming the move had caused undue hardship for family members seeking to visit him.
Our images show how, since his return to Dublin, Doyle has been posing in various stages of undress in his prison cell.
One image shows Doyle displaying a tattoo he got in memory of his brother Patrick (Paddy) Doyle who was shot dead in Spain.
Hitman Patrick (27) was gunned down on February 4, 2008 while travelling as a passenger in a car driven by since murdered friend and fellow criminal Gary Hutch.
Their involvement in serious organised crime had taken them to Spain, where they were closely associated with the Christy Kinahan crime empire.
Doyle was shot dead shortly after he had left a gym. Gardai believe Patrick Doyle was murdered after crossing the Kinahan gang after arriving in Spain in late 2005.
Doyle had left Ireland on the run from both the Garda and his criminal enemies.
Despite the belief by gardai that Paddy Doyle was murdered as a result of a row with the cartel, brother Barry remains closely aligned with the murderous Kinahan mob.
Like his brother Paddy, Barry Doyle is a gangland killer.
He is currently serving a life sentence for the shooting dead of rugby player Shane Geoghegan in a case of mistaken identity in Limerick in 2008.
He was paid by the McCarthy-Dundon gang to shoot dead one of their rivals but mistook Mr Geoghegan for the intended target. The murder of the intended target had been ordered by Limerick mobster John Dundom.
In May 2019, Doyle failed in an appeal of his sentence to the Strasbourg-based European Court of Human Rights. But the court upheld a previous finding by the Supreme Court against Doyle's claim that he was deprived of access to legal representation during crucial interviews by gardai.
Although Doyle had been given unrestricted access to his lawyer before and between police interviews, a solicitor's presence during the interviews was denied in line with the then practice by the police. That practice has since been changed.
The European Court found that restrictions on Doyle's access to a solicitor during interview had not irretrievably prejudiced his trial and so upheld the Irish Supreme Court.
Doyle had been arrested in February 2009 and was taken to a police station, where he was given immediate access to a solicitor, with whom he consulted prior to the first police interview.
He was subsequently interviewed many times and had access to a solicitor, both in person and by telephone, between interviews and for as long as he or the solicitor requested.
He admitted killing Geoghegan in the 15th interview and gave a number of details about the crime.
The disputed interview with Mr Doyle, his 15th and one in which he told gardai: "Yeah, I shot him", was video recorded.
Doyle later refused to name anyone else involved but removed a set of a rosary beads from around his neck, a memento of his own dead brother, for gardai to give to the Geoghegan family as a mark of his remorse.
In a separate failed attempt to overturn his sentence at the Court of Appeal, Doyle alleged gardai induced an admission of the murder from him but the court found Doyle knew what he was doing when he made the admission.
That court noted it was Doyle's solicitor who approached gardai with an offer Doyle would say he killed Shane Geoghegan if gardai agreed to release his girlfriend, the mother of his then one-year old daughter, from custody.
In August 2013, notorious Limerick criminal John Dundon was found guilty of ordering the murder by the three-judge Special Criminal Court.
Marking Shane Geoghegan's 13th anniversary on Tuesday last, Garryowen FC tweeted: "Thinking of our teammate and friend today, Shane Geoghegan. Gone but never forgotten."