There they joined a former garda Daniel Hickey, who was jailed for three years for his part in an assault on a man in Waterford city. He was brought there from the Midlands the previous weekend.
Dillon O'Brien is serving four years for smuggling drugs, alcohol and mobile phones into Mountjoy Prison. He was recently involved in a fight with lifer Warren Dumbrell, which he is said to have won.
O'Brien (38), from Clonsilla was in charge of landing B3 in the prison, and trafficked heroin and mobiles to an inmate.
He had been a cocaine addict, but had taken professional help.
In February 2010, former prison officer Thomas Corry was jailed for seven years with two suspended after he admitted supplying inmates with drugs and mobile phones over five years.
Corry, a father of three from Aughrim, Scariff, Co Clare, had almost 30 years' service when he was caught smuggling drugs, alcohol, knives, mobile phones, chargers, Bluetooth headsets and razor blades into Limerick.
He pleaded guilty to having quantities of cannabis resin, cocaine and prescription drugs for sale or supply at Roxboro Road, Limerick, on March 16.
Corry had tried to smuggle in a bag containing cannabis resin worth €900; cocaine worth €644; 365 alprazolam tablets; 144 diazepam tablets; 31 mobile phones, 34 chargers; seven sim cards; 22 Bluetooth headsets; a 7up bottle containing two litres of alcohol; 94 sets of razor blades; four batteries; four earphones; two penknives and a screwdriver.
He told gardai he had been smuggling phones and drugs into the prison for five years.
In the early hours of January 29, 2010, Anthony Holness was 'caught short' while walking home from a night out when he was bundled to the ground by Gda Hickey who had used a canister of pepper spray.
He was then punched in the head while he lay on the street. Another former garda, John Burke, involved in the same incident was released early this month from the open prison.