Police Minister Anne Tolley is considering plans to introduce a sex offenders' register.
Police and Corrections began work on proposals earlier this year after it was revealed a convicted paedophile was found to be working as a teacher.
But the register will not be open to the public, just officials with security clearance.
"I'm coming to the conclusion that that might be the most effective way," Tolley said.
Figures released this year show the number of convicted sex offenders who breached extended supervision orders rose from 56 in 2008 to 72 last year.
Tolley is concerned about the ad hoc way government departments share information on offenders. A central index - including those who have name suppression - may stop dangerous, and often manipulative, offenders slipping through the cracks.
"[Currently] you are reliant on individual protocols negotiated between different departments to get access. If you had a central register that wasn't accessible to the public but ... to ... a wide range of groups, perhaps at different levels with security, that might be a better way to keep track of where these people are."
The register would be based on a British model, she said. She has also talked to former Act MP Deborah Coddington, who drafted legislation to implement a register in 2003.
But a register may not have exposed Terito Henry Miki, 40, who assumed fake identities and used forged documents to work in several schools with children as young as 5.
He was snared when a member of the public recognised him driving a van-load of children and he was arrested for breaching extended supervision.
This month he pleaded guilty to seven charges of using a document for a pecuniary advantage and four counts of breaching a supervision order.
Miki was jailed for two years in 2004 on three counts of indecent assault and two of common assault on a 14-year-old. A warrant for his arrest was granted in May 2004 but he allegedly evaded arrest until late 2009.
In 2010, he was issued with a renewed supervision order but got provisional teacher registration under a new name and managed to secure teaching jobs.
Education Minister Hekia Parata launched a ministerial inquiry when the case came to light, headed by former ombudsman Mel Smith.
Police and Corrections have now exchanged the work they have done and will report back to Tolley in a couple of weeks.
The Government will consider the introduction of the register once the ministerial inquiry into the case wraps up.
The case has also prompted Corrections to resume the trialing of GPS tracking equipment for offenders on home detention and parole.
A pilot last year, using bracelets, failed because the technology was "too clunky". A second trial, using new lightweight devices, is now under way.
Police and Corrections are permitted to share information on sex offenders with the Social Development Ministry, Housing New Zealand, and Child, Youth and Family. In February the Government introduced the Privacy (Information Sharing) Bill to allow a better exchange of data in the public service.