Labour says it's a worry that 167 New Zealanders already deported back here this year won't be subject to any new monitoring under the Government's upcoming regime for supervising offenders arriving in the country.
And Sensible Sentencing says the changes don't go far enough.
Nearly 600 Kiwis are in the process of being deported under Australia's new anti-terrorism policy.
However, the current law means only the very worst offenders can be monitored and supervised when they get back here, with many others - still potentially high risk offenders - basically left to their own devices.
The new monitoring regime will apply automatically to returning offenders who were sentenced to more than one year in prison in another country, and return to New Zealand within six months of their release.
But none of the law changes will be retrospective and Justice Minister Amy Adams has confirmed that means 167 Kiwis already deported this year won't be subject to any new monitoring.
"It is a bit of worry that we've got 167 already in the country that the police would probably be concerned about," Labour's foreign affairs spokesman David Shearer told ONE News.
We want a publicly available register- Garth McVicar of the Sensible Sentencing Trust
Ms Adams says there's never an assurance that anyone released from prison in New Zealand or anywhere else won't go and commit serious offending. "Unfortunately sometimes that happens."
Green Party co-leader James Shaw says the new monitoring regime is only necessary because Prime Minister John Key "failed to get any concessions" from his Australian counterpart Malcolm Turnbull.
The monitoring regime will also mean all returning offenders can be fingerprinted and photographed and more serious offenders may have to submit DNA samples.
But Garth McVicar of the Sensible Sentencing Trust says it's not enough.
"I think what we really need is to be able to utilise the eyes and ears of the public. So we want a publicly available register," he said.