Nearly 80 convicted sex offenders have failed to alert gardaí of their whereabouts or the aliases they are using in the past 12 months.
Under current laws, people convicted of a sexual offence are required to notify gardaí of their home address, any names they use and if they plan to leave the country for more than a week.
Those found to have breached these requirements can face a maximum penalty of five years’ imprisonment or a fine of up to €10,000.
There are currently 1,708 people recorded at the Sex Offenders Management Intelligence Unit and there have been 76 breaches of the laws since last October.
However, Independent TD Denis Naughten believes this figure is only the tip of the iceberg and the “vast majority” are breaching the Sex Offenders Act.
The Roscommon-Galway politician, who has long campaigned for tougher legislation on sex offenders, said gardaí do not have the resources to enforce the laws.
“We are expecting gardaí to try and enforce the theoretical sex offenders’ register we have when they don’t have the basic tools to do that,” Mr Naughten said.
“Those 76 people have come to the attention of gardaí for some other purpose.
“Every five days on average you have someone coming to the attention of gardaí for some purpose, and they find out they are also breaching the sex offender registry.
“But gardaí aren’t actively enforcing that because it is impossible for them to do that, the way the legislation is currently drafted.
“The difficulty is those 76 are just the very sliver of the tip of the iceberg of breaches of the act.
“The vast majority of the people on the sex offender registry are breaching it, but if they don’t come to the attention of gardaí they are unlikely to be charged.”
Junior minister Hildegarde Naughton, responding to a parliamentary question by Mr Naughten, said gardaí are responsible for monitoring sex offenders under the Sex Offenders Act 2001.
She said the Sex Offender Management and Intelligence Unit unit “liaises on a daily basis with nominated divisional inspectors and their team through the garda regions with regards to the maintenance of records and the monitoring level of registered sex offenders in their area”.
It comes as a bill strengthening the monitoring and management of sex offenders is expected to be published by the Government within the next month.
The new laws will see certain high-risk offenders being electronically monitored and allow gardaí to fingerprint and photograph sex offenders to confirm their identity.
The Sex Offenders (Amendment) Bill also mandates for offenders to notify gardaí of their change of address within three days, compared with the current seven-day period.