Sundayworld.com can reveal that the prisoner is cartel member Peter ‘Peadar’ Keating, who admitted directing the activities of the crime group in their failed attempt to murder Hutch gang member James 'Mago' Gately and was jailed for 11 years at the Special Criminal Court on September 2 last.
The incident happened on the day that the gangster was sentenced.
Passing sentence Mr Justice Tony Hunt said that Clondaklin criminal Keating (40) was a "repository of trust and confidence" for the organised crime group.
Speaking outside court on the day, gardai said that the investigation highlighted the transnational outreach of organised crime, whose members "do not recognise law or respect our borders".
Today it was revealed that three of the officers spent a portion of the day in Dublin drinking alcohol and all were unfit to drive the prison van back to Portlaoise that evening.
As a result, the fourth, who was the senior officer, had to drive the vehicle. As the person in charge of the escort, the senior officer should not have been driving, it was reported.
The account is being treated as credible.
The Irish Prison Service has confirmed to Sundayworld.com that a major investigation is in place into the allegations but no staff member has yet been suspended from duty.
“The Irish Prison Service sets high standards in respect of its staff and requires that all staff carry out their duties with integrity, commitment and professionalism at all times,” a spokesman said in a statement.
“In circumstances where the conduct of a staff member falls below the high standards expected, this is treated with the utmost seriousness in accordance with the Civil Service Code of Discipline.
“The Irish Prison Service can confirm that it has commenced an investigation into allegations of a breach of escort protocol by a number of prison staff under the Civil Service Code of Discipline,” he explained.
Sources said today that gardai are also “extremely concerned” about the matter but have not at this stage launched an investigation into it.
Keating was an amateur football manager who went onto become one of the most senior members of the Kinahan cartel and had "tried to present himself as a community man", according to sources.
He had pleaded guilty to directing the activities of a criminal gang involved in the failed attempt on Hutch associate James ‘Mago’ Gately in 2017.
The murder plot was foiled when Estonian hitman Imre Arakas was arrested and a weapon seized after he travelled to Ireland for the hit.
Following a major investigation by the Garda ‘s Drugs and Organised Crime Bureau (DOCB) it emerged that Keating was one of the main organisers of the plot.
Keating, of Rowlagh Green in Clondalkin, was also heavily involved with and the manager of his local amateur soccer club Collinstown FC.
A close associate of his, senior cartel figure Sean McGovern from Crumlin, is also under investigation in relation to the Gately plot and is currently in Dubai with mob boss Daniel Kinahan.
Keating’s conviction and lengthy sentence is considered one of the Garda’s biggest successes in their fight against the international cartel.