A former prison officer, who smuggled mobile phones, drugs and alcohol into Mountjoy Prison over a two year period, has been sentenced to four years in prison.

Dillon O'Brien, a father of three from Charnwood Meadows in Clonsilla in Dublin, pleaded guilty to trafficking mobile phones, cocaine, heroin and vodka into Mountjoy Prison between January 2005 and March 2007.

The 37-year-old also pleaded guilty to possession of cocaine at his home on 15 March 2007.

Judge Katherine Delahunt told O'Brien he was a person who had been placed in a very trusted position which he had grossly abused in a very fundamental way.

She said his involvement in these crimes was at the very high end of the scale.

Judge Delahunt said she had to impose a custodial sentence even though she said she knew this could be more difficult for O'Brien in light of his former profession.

O'Brien's lawyers previously told the court that he had carried out the crimes because he was addicted to cocaine and steroids and had received small amounts of cocaine and some money in return.

Thomas Hinchon, a prisoner who is serving a life sentence for murder, was sentenced to three years for possession of a mobile phone and conspiracy to convey cannabis into the jail.

The judge asked for a probation report in respect of his brother Sean Hinchon from St Ronan's Close in Clondalkin who gave phones and drugs to O'Brien to bring in to his brother.

His case has been adjourned until next March.