Minister for Justice Minister Dermot Ahern has said he is concerned at the low numbers of sex offenders attending treatment in prison.
Official figures have revealed that out of 578 convicted sex offenders released from prison in the last five years, just 42 had completed a highly intensive rehabilitation programme.
From a further 115 due to for release in the next 18 months, only 10 have finished the scheme.
"The low number of sex offenders attending treatment is not because there is a shortage of places on treatment programmes, but because a lot of sex offenders are not willing to participate in the highly demanding, intensive sex offenders treatment programme that is available in prison," Mr Ahern said.
"If I thought it would do any good I would certainly consider introducing mandatory treatment for sex offenders but all the expert advice I have received is that mandatory treatment simply does not work."
Mr Ahern said experts disagree on how effective treatment is for sex offenders and studies show the risk of sex offenders who are motivated to participate in treatment and who receive supervision and support in the community can be reduced by 20 per cent to 40 per cent.
"So even in the ideal circumstances treatment does not offer a cure for all," he said. "There is no simple, instant solution."
Mr Ahern said expert group is examining the best way to treat and manage sex offenders by looking at the best practice in Europe and America and at how more prisoners can be induced into treatment programmes.
"The Irish Prison Service is also looking on how temporary release and different prison regimes could be used to provide incentives to participate in treatment programmes," he added.
"I expect the group to publish a paper before Christmas setting out all the different options so that we can have an informed debate and different organisations can put forward their views."
Groups representing sex abuse victims today called on Mr Ahern to implement and resource mandatory treatment for sex offenders in prison. Concerns were also raised that the only sex offender programme in a prison has been suspended while a review is carried out to expand the service.
One in Four's Maeve Lewis said it was outrageous that offenders who have destroyed people's lives can choose whether or not to attend programmes in prison.
"Mandatory treatment must be put in place," she said. "While it may be a hard pill to swallow, rehabilitation must be the focus if we are to protect children. Research shows that if sex offenders undergo effective treatment, the rate of re-offending drops as low as 3 per cent."
Ellen O'Malley-Dunlop, of Dublin Rape Crisis Centre, said the programme in Arbour Hill is the only programme of its kind in the Irish Prison Service.
"It is imperative that it, not only continues, but is expanded, so that all of the sex offenders in our prisons can avail of the treatment," said Ms O'Malley-Dunlop. "International research continually points to the positive effects of rehabilitation in this area. We want to make our society safe for our children and for the most vulnerable in our society."