Keeping Children Safe, a police disclosure scheme which allows the public to apply for information about an individual who has access to a child, received 258 applications for information since its launch last March.
Registered sex offenders were reported in 64 cases but information was only given out in 26 cases.
Anyone can report an individual but only the parent, guardian or carer is entitled to information.
National co-ordinator Willie Manson said it was not always appropriate or necessary to disclose information, such as cases where the guardian was aware the individual was a sex offender.
However, he stressed that all cases were investigated and action was taken where appropriate.
A total of 55 child concern reports were submitted for children in contact with sex offenders.
The case was then referred to police, social work and health workers to decide if the child was at risk.
Some 114 reports were submitted to advise police about individuals with no relevant disclosure offences but with enough suspicion to remain on the police radar.