The register would not be available for members of the public to view.
"There is very good evidence that, particularly those high risk offenders will be driven underground if they are named and shamed," Ms Tolley said
Police would be required to develop "very good security" around the systems to ensure as much as possible the information was not leaked, she said.
In recent years there have been high profile leaks from agencies such as ACC and EQC, revealing private details of thousands of claimants.
Associate Professor Ian Lambie from The University of Auckland's School of Psychology said if the agencies involved were able to ensure the register was kept confidential from the public, and it was used to keep children safe and minimise the risk of these offenders reoffending, there would be some merit in having the register.
"There would have to be some pretty tight controls and I suppose some safeguards of the names and processes in place to ensure names did not get out into the general public."
It could be dangerous for offenders, should their names be exposed by any leak of the register, Prof Lambie said.
The register was a good idea in principle, but would do little to stop paedophiles offending against children, he said.
Defence lawyer and prison reformer Peter Williams QC said he did not think the register would achieve very much.
"I think the police have a certain amount of licence in cases where you have paedophiles near schools.
"I can understand the philosophy or the ethos, and I think it's probably well intended. But on the other hand, you've got parole and other ways that people can be watched. I don't think it's necessary to have these things published."
If the list was ever leaked it could be horrific for some people, he said.
Labour Party Police and Corrections spokeswoman Jacinda Adern said they were not opposed to information sharing, but the bottom line was that no such list, register or information should ever be made public, or shared publicly.
"While the Government has indicated that this would not be the case, we want to see protections in place to prevent this from occurring."
But the Sensible Sentencing Trust has called for the register to be public knowledge.
"The fact is that naming these offenders will help stop the continuation of abuse, it will stop them reoffending," spokeswoman for Prevention of Child Abuse Nadia Crighton said.
"This is about protecting our children, it's about time their rights come before those who want to abuse them."
