One of the leading internet providers in Ireland has announced it is to block websites containing child sexual abuse material.

This will apply whether or not the sites are accessed deliberately or mistakenly.

UPC has signed an agreement with the gardaí that will see them block domains and addresses based on a list.

If someone using a UPC internet attempts to access the sites, they will get a message explaining why it has been blocked.

An Garda Siochána is also in negotiations with other internet providers to get them to block child sex abuse sites as well.

However the Garda Commissioner Noirin O'Sullivan says existing privacy laws prevent the automatic transfer of customer data to the gardaí.