Prison chaplains have expressed concern that new Government measures to eradicate heroin from prisons are not backed by support such as counselling or rehabilitation.
A new strategy of compulsory drug-testing for prisoners, along with addiction counselling and treatment, is due to be implemented in prisons this year.
This follows a pledge in the Fianna Fáil/Progressive Democrat Programme for Government that steps would be taken to "completely end" all heroin use in both jails and places of detention.
However, prison chaplains yesterday said the plan was "ludicrous" given the lack of treatment or counselling services available.
Father Ciarán Enright, of the National Prison Chaplains, said: "Rehabilitation for people with addiction problems is non-existent in prisons. Anything designed to help people in prisons is welcome, but it can't be in isolation from addiction support services."
He said the scale of the drug problem varied from prison to prison, but that rehabilitation services were inadequate across the entire service.
"Regularly the courts are remanding people in custody to avail of treatment, but in many cases the service doesn't exist. We can't go on pretending there is this opportunity for people to reform and go on to live drug-free lives," he said.
The Irish Prison Service confirmed yesterday that mandatory drug-testing would be expanded across the prison service this year and used in cases where it was considered appropriate.
Additional measures, such as expanding the issuing of photo ID cards for visitors and increasing the numbers of CCTV cameras, would also be put in place.
A Prison Service spokesman pointed out that drug-testing occurred in the drug-free wings of prisons, including Mountjoy and St Patrick's Institution, as well as at open prisons.
He defended the rehabilitation services and said that additional psychologists and nursing staff had already been appointed.
The spokesman said that the Prison Service remained committed to developing and expanding treatment programmes in conjunction with community and health agencies, subject to available resources.
"Considerable resources have gone into drug treatment programmes and rehabilitation. Our primary focus is on keeping drugs out of prison . . . we've done an awful lot in terms of building up the infrastructure and we're constantly adding on to counselling and other services," the spokesman said.
Some prison doctors, meanwhile, have expressed concern over ethical issues relating to compulsory drug-testing.
The Irish Medical Council has received correspondence asking whether the mandatory testing of prisoners is acceptable when it is part of what is described as a political policy rather than solely for health reasons.
A spokesman for the Prison Service said that prisoners who tested positive for drugs may be removed from drug-free prison wings or, in some cases, moved to other prisons. However, the emphasis would be on offering rehabilitation rather than on penalising those who tested positive.