Convicted murderer Brian Rattigan has become the first person in the State to be found guilty of drug dealing from behind bars.

The 32 year-old, formerly of Cooley Road, Drimnagh, has been convicted of the possession of one million euro of heroin for sale or supply, while an inmate in Portlaoise Prison.

When gardaí raided Brian Rattigan's cell on the E landing at Portlaoise prison, the convicted murderer was lying on his bed with a mobile phone in his hand.

Following a trial at the Special Criminal Court the 32 year-old was found guilty of drug dealing from behind bars - the first person in the State to be convicted in such circumstances.

Rattigan sent text messages referencing “half bars,” and "9" allocated to names such as “Gangko” “McGyver”.

The court said it was satisfied the list, taken in conjunction with notes found in his cell amounted to directing drug dealing.

The Drimnagh man, who is serving life for the murder of Declan Gavin in August 2001, will be sentenced for this offence next month.