It's alleged that recording devices may have been placed in changing rooms used by children.
A swimming coach has been arrested as part of an investigation into reports of recording devices placed in children's dressing rooms.
The man was questioned earlier this week about the alleged sexual exploitation of children.
This investigation began after a number of complaints were made to Swim Ireland who then called in Gardai.
Its alleged that recording devices may have been placed in changing rooms used by children before and after swimming lessons.
Gardai say a man in his 30's was arrested as part of their investigation on Tuesday.
He was detained under section 4 of the Criminal Justice Act and questioned for a number of hours at a West Dublin garda station about alleged offences contrary to the criminal law sexual offences act.
He was later released without charge and a file is being prepared for the DPP.