A hundred years ago it was acceptable to simply turn the key on a door and lock away a criminal. Nowadays terms such as treatment and therapy are being embraced by the Prison Service as the tools to achieve prisoner rehabilitation and the ultimate goal of protecting society on their release.

"When people are in the care of the State there is a moral and legal requirement to attempt to rehabilitate them. Anything less is a denial of State responsibility," according to Dr Valerie Bresnihan, the chairwoman of the Irish Penal Reform Trust.

She dismisses arguments that some prisoners are not suitable for certain programmes that require intensive group work. Anthony Cawley, who committed suicide in Wheatfield prison last week, was an example of a prisoner who was assessed for the specialised sex offenders' programme in Arbour Hill Prison but was deemed unsuitable and instead was provided with one-to-one counselling.

"He said he wanted help. How ready do they wish prisoners to be?" added Dr Bresnihan.

This month's official figures indicate that 357 convicted sex offenders are being housed in Irish prisons. A further 39 are on remand or going through the courts. The Arbour Hill programme admits 10 prisoners once a year through a strict selection programme. Staff from the Department of Justice psychology department operate the programme. Of 103 sex offenders released on completion of their sentences in 1998, 11 had completed the specialised programme. Eighty were released in 1999, with five having completed the programme. Preparatory work is continuing under the supervision of the Director-General of the Prison Service for the introduction of a second similar course in the Curragh Prison later this year.

However, there have been calls for the expansion of the sex offenders' programme beyond this, and most recently the governor of Wheatfield, Mr John O'Sullivan, told The Irish Times it should be expanded to every prison holding sex offenders. "Prisoners need more opportunities to address their difficulties. We should stop now and look where we are going," he said.

In a Dail address this month the Minister for Justice, Mr O'Donoghue, defended his Department's record in the area and said three other forms of treatment were available to prisoners in addition to the opportunity to apply to the specialised programme.

"The reality is that many sex offenders in custody are either unsuited or unwilling to participate in intensive group programmes like the course at Arbour Hill . . . due to insufficient motivation, emotional immaturity or otherwise," he said.

Individual counselling, the psychiatric service and new group-work courses such as the multidisciplinary thinking skills programme available in Arbour Hill and Cork Prisons were also on offer, Mr O'Donoghue said. During the debate one TD criticised the Minister for providing the equivalent of two full-time psychiatrists for more than 2,600 prisoners. Those working within the prison system agree the so-called thinking skills programme, now in its third year, offers a first line of approach for these prisoners to address issues such as anger management and the evasion of personal responsibility. However, one prison officer said there was an absence of any "sentence planning" for prisoners.

"There is a clear path they could be guided on, but most don't get the chance. The Department uses phrases like `You can't force prisoners to apply' but they are given no real incentives. It should be tied to the granting of remission and you would see a lot more prisoners motivated to apply," the officer said. Another man working within the prison system said some of the agencies in the Department illustrated "a tendency to protect their own niche and status rather that consider what's best for the prisoner". He added that many prison officers felt frustrated that they were not being trained to help deliver sex treatment courses under supervision, a model at work in other European countries that would allow the programme to expand.

However, the governor of Mountjoy, Mr John Lonergan, has stressed that sex offending is a complex area. "There is an increasingly varied clientele and variety of offences so a certain level of expertise is necessary. It is important to build a multidisciplinary approach but it is very delicate work and must not be rushed into," he said.

However, he added that specialised programmes did not provide all the answers. "Treatment does not eliminate the chances of reoffending. Some individuals are going to benefit, others are always going to be high-risk," he said.

If reoffending is a reality, then so, too, is the emergence of new offenders. Only last week, as Anthony Cawley thought of ways to end his life in his prison cell, a 16-year-old boy attacked and raped a teenage girl at a bus-stop on the Swords Road close to the airport as evening traffic zoomed by. The attack was eventually stopped by a passing off-duty garda and the boy was arrested. Now that he is in custody, the system must decide what to do with him along with so many others.