Cumbria Police have received 14 applications from local people to use Sarah's Law.
The scheme was introduced following the death of Sarah Payne.
It allows people to ask police details about individuals who they suspect might harm children.
The NSPCC have revealed that across the country, only one in six applications results in the disclosure of information.
Cumbria Police has had a high number of successful applications as nine out of the 14 have resulted in information being given since April 2011.
Peter Wanless, NSPCC chief executive, said: “We are both disturbed and surprised by this wide discrepancy of figures across the country, revealing that there is a postcode lottery when it comes to how forces deal with Sarah’s law.
“Families need to know if there are individuals in their area who pose a risk to children. How can you expect parents to make the right choices in order to protect their children if they don’t know who is a threat?”
“The police need to be proactive in empowering communities to protect vulnerable children. The wide variation in disclosure numbers doesn’t breed confidence that the scheme is being understood or applied consistently and that is a concern. While there may be very good reasons for not disclosing information held to applicants, some forces seem to be too cautious which could put children at serious risk of harm. We need to see regular independent evaluation of this vital law to make sure it’s working as it should.”