At least 900 convicted sex offenders have been released from prison to live in the community unmonitored despite being on the sex offenders' register and despite refusing to undergo treatment while in jail, it has emerged.
The true number is likely to be much higher because those convicted before the sex offenders' register was established in 2001 are under no legal obligation to register with the Garda when they leave prison.
Other sexual offenders convicted since 2001 can live untracked and unmonitored because their periods on the register are expiring.
New figures released by the Department of Justice show there are now 1,069 offenders on the sexual offenders' register. Of these, 112 are currently under the supervision of the Probation Service.
The remaining 957 are not being monitored by Probation and Welfare.
While the Garda has a role in investigating any registered offender who fails to comply with his obligations - such as alerting gardaí to any change of address - the force has no role in supervising or monitoring them.
Other data released by the Department of Justice show sexual offenders currently in prison are unwilling to participate in treatment programmes.
Of the 291 sex offenders in jails across the prison system, only eight have agreed to participate in the sex offenders' programme. The 11-month course is in Arbour Hill Prison, Dublin, where 87 sex offenders are currently imprisoned.
The department's data show that since the treatment programme began in 1994 only 128 prisoners have completed it. This means an average of just nine sex offenders released in each of the last 13 years has completed the programme.
A response by Minister for Justice Brian Lenihan to a parliamentary question tabled by Fine Gael's Alan Shatter also confirms that neither the Irish Prison Service nor the Garda have any record as to which released offenders were willing to undergo less structured treatment, such as one-to-one counselling, while in jail.
The response notes that "it is not possible to quantify with absolute accuracy participation in all forms of rehabilitation".
Mr Shatter said he found the lack of records "not only extraordinary, but alarming".
"We obviously know who has taken part in the formal programme, but you would think somebody would be keeping track of other offenders who had or hadn't shown a willingness to at least talk to a counsellor.
"I would have thought this kind of information could have been given to the gardaí to help them assess the highest risk offenders after release."
He said the fact so few released inmates were being monitored by the authorities underlined the "gross inadequacies of the services currently in place to protect the community".
"Despite all the revelations of the last 10 years we're still falling short to an astonishing degree," he said.
The sex offenders' register was established with the enactment of the Sex Offenders Act, 2001. Offenders on the register must keep gardaí informed where they are living and must inform them of any change of address, or plans to travel either inside or outside the jurisdiction.
An offender can be placed on the register for an indefinite period if they are jailed for two years or more. If imprisoned for between six months and two years, the period on the register is 10 years. For a sentence of less than six months, a seven-year register period applies. If an offender is not jailed the period on the register is five years.