Details have recently emerged that Murphy received an out of court settlement of 20,000 in 2004 from the state for the "degrading" way in which he was treated.

This included being locked in a padded cell in Mountjoy for 79 days in a row.

A report on Murphy's treatment in Mountjoy Prison, which was carried out by Dr Valerie Bresnihan for Murphy's solicitor, catalogues the appalling way Murphy was allegedly treated in prison.

During his time in a dark cell or "pad" in Mountjoy, where there is "almost no air" and the "windows are sealed", Murphy was not given any toilet paper in case he would set himself on fire. He had to defecate into a bucket.

In the pads, "male prisoners were obliged to wear underpants only.

Some difficult or very mentally ill prisoners were kept naked for their own protection. The report describes how the pads were never cleaned and how Murphy "drank his own urine" as he was so ill. He "lost track of day and night" while he was locked up in conditions Dr Bresnihan believes amounted to an "abomination."

Murphy has been in and out of institutions since he was 12-yearsold and, according to the report, has accumulated "several psychiatric and psychological reports documenting [his] mental state and stays in the pads. . .He has been diagnosed as having a major personality disorder. . .He appears to be a difficult prisoner and has been aggressive on occasions." He has made several suicide attempts, "suffers from paranoia and has been admitted to the Central Mental Hospital", the report claims.

Padded cells are often used to hold prisoners who are awaiting admission to the Central Mental Hospital, Dr Bresnihan's report says. Murphy was sometimes isolated there following attempts to kill himself.

"If David was suicidal, depressed or paranoid he was sent to the pads and he was out there for varying lengths of time, " she says.

The report claims that Murphy was placed in a padded cell while under suspicion for a crime it transpired he did not commit and this is described as "deeply worrying".

In a statement about this punishment (which is contained in the report), Murphy says: "That night I tried to kill myself as I was being blamed. They put me in the basement for protection. I was in there for five weeks and I lost track of time. I was not handcuffed but I was in a body belt."

Murphy spent 133 days in padded cells in Mountjoy between 1997 and 1998 including that five-week period. He should have been getting medical attention for his mental illness, the report says.

In the conclusion of her "Report on Padded Cells in Mountjoy Prison", Dr Bresnihan states: "It is clear that society has failed David Murphy if it is true that he was initially in prison since he was 12years-old. Certainly the prison system . . . both medical and management . . . has failed him. This case shows up an almost total neglect of the mentally ill in prisons in this country.

Dr Bresnihan is running as an independent "Voice for Social Justice" candidate for the next Seanad elections and she hopes that election to Leinster House will give her a louder voice to campaign for marginalised groups such as the mentally ill in prisons.