A former guard at Manus Island says refugees there are violent and New Zealand should take back its offer to accept them, but Immigration NZ is confident in its vetting systems.
The government has said its offer to re-home 150 detainees still stands, despite revelations of child sex abuse and drug dealing by some.
John Horler, who was a guard in the Papua New Guinea detention centre from 2013 until last month, told Checkpoint he witnessed many episodes of violence.
"At one stage we were allowed to restrain them, we could keep the violence to a minimum. As soon as the centre itself was deemed illegal by the PNG government, we weren't allowed to lay our hands on anything.
Mr Horler said most of the violence was against other detainees but some staff were also injured.
However, Amnesty International NZ executive director Grant Bayldon responded by saying the refugees had been subjected to cruel, inhuman treatment.
"We'd be relying heavily on screening from the New Zealand government," he said.
https://www.radionz.co.nz/national/programmes/checkpoint/audio/2018622098/manus-is-refugees-treatment-cruel-inhuman-amnesty-international "They have a very thorough process for vetting people for potential refugee resettlement" - Amnesty International NZ executive director Grant Bayldon
"But what's really important here is that we have to remember that even if there are one or two people - as you'd expect in any large group of people - who've committed crimes or done things, that doesn't mean that everyone is responsible for that at all.
"You've got to remember that it's people that have fled their homes in - of course - extremely difficult circumstances, and they've been detained indefinitely, so you'd expect that they'd be under some stress.
He said the guard's claims had never been reported to police, and dubious claims about those held at the facility had been made in the past.
When a group of soldiers had attacked the refugee centre in a drunken rampage after a football game in April, the Australian government had made outrageous claims that turned out to be untrue.
"So really you have to be very dubious of claims made against any big group of people and take the time to investigate those properly," Mr Bayldon said.
Immigration New Zealand said it was confident its systems for vetting refugees are robust enough to keep out criminals.
Its national manager for refugees Andrew Lockhart told Checkpoint everyone considered for resettlement had already been screened by the United Nations Refugee Agency, the UNHCR.
He said New Zealand officials would also make their own security and character assessments, and carry out health checks.
Mr Lockhart said about 10 percent of refugees were turned down for resettlement in New Zealand.