However, some parents have claimed the programme does not go far enough, calling for information on all sex offenders released from prison to be made public.

Chief Inspector Knox said, “I’m a parent myself and the thought of losing a child, never mind a child to a sex offender, is your worst nightmare.

“But I firmly believe that the kind of disclosure we’re doing here is the correct way to do it.

“I don’t think giving a blanket disclosure on every sex offender that gets out of prison would meet our needs. They would go underground.”

The nine-month pilot — which was first revealed in the Tele in May last year — will run in Tayside until the end of May 2010, allowing a “controlled disclosure of information” to people with concerns about somebody in contact with their child.

Since the initiative began in September, there have been a total of 33 applications, with officers disclosing in four cases, including three involving a person on the Sex Offenders’ Register.

Last month, two disclosures were made confirming information, as a direct result of phone calls from members of the public.

It is understood that a number of other calls have resulted in police making intervention “behind the scenes”.

If a person is found to have convictions for sex offences and a youngster is found to be at risk of harm, then child protection measures can be put into action.

But anyone making an inquiry must confirm they are supplying correct information and could face legal consequences for false claims.

Chief Inspector Knox said vigilante activity as a result of the information given out has not proved a concern.

He added, “It’s vitally important people come forward. This scheme won’t work without people coming to us and asking us for information.

“Any member of the public out there who has got a concern about somebody who has got access to children can contact to us.

“We will only disclose information to people who can protect the kids, so it will be the parents who get the information, but it’s vitally important that the public come forward and speak to us about this.”

Margaret Ann Cummings, the mother of murdered Glasgow schoolboy Mark Cummings today said the scheme was a “good step forward”, but doesn’t stretch “as far as we wanted it to go”.

She said, “There were other communities that had concerns about him, but obviously didn’t know where to turn to, or who to go and see to have the checks made on him.

“When a sex offender is in the area and going about doing what they are good at doing — hiding the fact that they are abusing kids — that’s what we’ve got to put a stop to.

“And the only way we can do it is having everybody in the community given the information, not us having to go down and seek the information.”

At any given time there are around 350 registered sex offenders in Tayside, more than 50 of them categorized as high risk.

Child protection charities Children 1st and Stop it Now are also involved with the pilot to provide support.