REVEALED: The 18 gangs who control Ireland's prisons
There are at least 18 major organised criminal gangs operating within the Irish prison system, vying to control an illegal world of drugs, mobile phones and contraband.
The notorious prison houses dangerous gangland figures such as Thomas Hinchon, Craig White and Barry Doyle.
Authorities have to keep track of multiple factions that are operating within Mountjoy’s historic stone walls but the jail is largely controlled by four main outfits.
Smaller groups, usually based on the part of Dublin they come from, toe the line as far as the Kinahan cartel are concerned.
Anyone connected to the Hutches has been transferred out of the jail or put on protective custody.
'Del Boy' Hutch was lucky to survive two attacks in the jail's B Wing, carried out by criminals keen to curry favour with the cartel, before being transferred last year.
Derek 'Del Boy' Hutch
Prisoners connected to the Crumlin-based faction headed by 'Fat' Freddie are key players when it comes to wielding the cartel's power.
Kinahan associates can also reach the A Wing, where murder accused Tossy Fox was stabbed after coming into conflict with the cartel.
Thomas 'Tossy' Fox
The Clondalkin gangster who controls the wing, Thomas Hinchon, has been actively involved the prison drugs trade as he serves out his life sentence for murder.
B Wing is in the hands of associates with the Coolock criminal known as Mr Big but also features veteran criminal Davin Flynn, who has close connections to the Kinahan cartel.
The biggest lock-up in the country, the Midlands Prison, with a capacity for 870 prisoners, is home to a number of organised gangs who are on separate blocks.
On the E Wing the man other prisoners fear most is gangster Christy Griffin, serving time for child sex offences, who controls the trade in illicit drugs.
'Fat' John McCarthy controls things in the C Wing along with convicted Murder Inc. killers David 'Frog Eyes' Stanners and Christopher 'Smokey' Costello.
McCarthy's cousin and one-time clan leader 'Red' Larry McCarthy is isolated from his one-time allies but now runs things on B Wing instead.
Members of a traveller crime family control the drug trade on the A Wing and are able to supply what's needed for the inmates on D Wing, throwing packages between the wings.
Crumlin gang leader Brian Rattigan is doing his life sentence for murder here.
Also incarcerated in the same block are three Dundon brothers, Wayne, John, Dessie and their faithful sidekick Nathan Killeen.
However, the No.1 when it comes to rank is Brian 'Tosser' Meehan.
Serving life for his role in the murder of Veronica Guerin, he recently clashed with UK drug dealer Perry Wharrie, who ended up in the protective custody area where the Dundons are also detained separately from the rest of the prison population.
E Wing is the domain of the dissident republicans, whose members belonging to ranks of the organisations such as The Real IRA and the New IRA.
They decide who can or can't be placed on the E Wings. They recently exercised their muscle when prison chiefs reversed a plan to shut down The Base, the basement wing used as the punishment block for E wing.
Members of the Hutch clan are now isolated from other inmates at Wheatfield.
They have been marked out for attacks thanks to the power and influence of the Kinahan cartel within the jail.
The Sunday World recently reported how the group were refusing to eat food prepared in the prison kitchen, fearing it could be poisoned.
Other landings hold members of west Dublin gangs from Clondalkin and Ballyfermot.
Beside Wheatfield in west Dublin, Cloverhill is a remand prison used for those in custody awaiting trial.
Visits are conducted behind a screen, which makes smuggling into the prison more difficult and denies gangsters a way of exerting control.
Most stays are relatively short-term and prisoners know this, preferring to behave before going on trial.
Although newly refurbished wings are now being used, the exercise yard in Cork is still not protected by a net meaning packages of contraband can be thrown in.
Compared to the Dublin and Laois jails it is relatively small, and more serious offenders from Munster are held elsewhere.
The illicit trade is controlled by Robert Crinnion, serving a 10-year sentence for a slash-hook attack, and his drug-dealing brother.
As a jail mostly used for long-serving sex offenders and killers doing life, it does not have a gangland presence.
Many of those detained would be considered vulnerable among the general population in other prisons.
Drugs are easily obtained in Limerick Prison, which has a capacity for 280 inmates.
Over the years various factions have held sway, depending on which gangs are serving time there.
At the moment the black market trade in contraband is entirely controlled by the Collopys.
Brothers Brian, Vincent and Kieran are all serving time there, along with Brian's son Kenneth.
Previously the Collopys spent time in the high-security Portlaoise Prison but eventually fell foul of Brian Meehan's gang and it's no longer an option as a place to detain members of the Collopy mob.
Rival Limerick factions are being held in Portlaoise and the Midlands, not just to prevent rival gangsters clashing while inside but also to prevent violence between visitors.
The County Roscommon lock-up serves as the jail for much of the west and north-west of the country.
The A Wing is controlled by associates of the Galway-based O'Loughlin gang, members of the Sweeney clan and wife-killer Michael Quinn-McDonagh.
The level of gang activity is such that much of the B Wing is taken up by prisoners who are on protection or have been moved there to be out of reach of the gangs.
Like other jails, the use of tablets is a serious problem but sources add that there has also been an increase in the heroin use in the jail.
The prisoner thought to be behind much of the gang activity on the B Wing is a Dubliner with connections to north Dublin criminal 'Mr Big', who also has a reach into Mountjoy.
Also in B Wing are a group of drug dealers from the west who have been key players in the local heroin trade.
Shelton Abbey and Loughan house
The low-security regimes at the open prisons in Wicklow and Cavan mean that the gangs have no leverage on which to base their power.
The prisoners are generally deemed to be low-risk and for convicts approaching the end of their sentences.
These prisoners do not want to be caught doing anything that could jeopardise their release.
Inmates are also regularly drug-tested and a failure means a ticket straight back to a closed-prison regime.
However, if they do want to get drugs or booze there's little to stop them picking up what they need from friends on the outside or a supermarket off-licence.
Dangerous gangland criminals are unlikely to ever be allowed into either prison.
Linda and Charlotte Mulhall
'Scissor Sisters' Linda and Charlotte Mulhall are undoubtedly the queen bees of the women's prison but don't operate as a criminal gang.
The women who get hold of drugs through visitors do so on their own initiative.