A total of 708 disclosures of paedophiles have been made across England and Wales, and Scotland, since powers under Sarah's Law were rolled out nationwide.
Sarah's Law - or the child sex offender disclosure scheme - allows parents, carers and guardians to formally ask the police to tell them if someone has a record for child sexual offences.
The Home Office developed the scheme to protect children.
Here are some key questions and answers surrounding Sarah's Law:
:: What is the background to the scheme?
It was developed in consultation with Sara Payne, whose eight-year-old daughter Sarah was murdered by a convicted paedophile.
Sarah, who lived in Hersham, Surrey, disappeared on the evening of July 1 2000 from a cornfield near the home of her paternal grandparents, Terence and Lesley Payne, in Kingston Gorse, West Sussex.
A body was found on July 17 2000 in a field near Pulborough, some 15 miles from Kingston Gorse where she had disappeared. It was confirmed as Sarah.
Roy Whiting was convicted of the abduction and murder of Sarah on December 12 2001 and sentenced to life imprisonment.
Whiting had previously abducted and sexually assaulted an eight-year-old girl, who cannot be named for legal reasons, and was sentenced to four years in prison.
Ms Payne campaigned in support of bringing in a scheme similar to Megan's Law in the US, which allows every parent in the country to know if dangeous offenders are living in their area.
:: How does the scheme work?
Anyone who wants to find out if someone in contact with a child has a record of child sexual offences can use the scheme.
Police forces process the application - but disclosure is not guaranteed.
However, an applicant can trigger an investigation to find out if a person has a known history even if there are no firm grounds for suspicion.
Grandparents and neighbours are also invited to use the scheme but it is most commonly used by parents and guardians.
:: Where the scheme is available?
The scheme is available across all 43 police forces in England and Wales, and in Scotland. It does not apply in Northern Ireland.
:: Who will the information be disclosed to?
The information will only be provided to the person making the enquiry.
The person receiving the information must agree to keep it confidential.
:: Were there any concerns?
There have been fears the scheme could drive child sex offenders underground, or cause vigilante-style attacks.
In the US, Megan's Law, which allows much more disclosure, including the publication of names, addresses and pictures of paedophiles in some states, has experienced such problems.
Under the UK scheme, a parent who is given information is not allowed to pass it on to other people.
The pilot did not throw up any such problems, but children's charities have warned that monitoring of the scheme must continue as it is rolled out nationally to ensure this does not happen.