The average cost of keeping a prisoner in 1996 was £46,500, the House was told in a written reply.
Responding to the Fianna Fail spokesman, Mr John O'Donoghue, the Minister for Justice, Mrs Owen, said costs in Portlaoise were highest at £104,268, and lowest at Loughan House - £33,640. At Mountjoy the cost was £46,743.
At Castlerea and the Curragh, the costs are estimated this year at £34,500 and £36,500 respectively.