Any Manus Island detainees taken in as refugees by New Zealand would be thoroughly vetted first, the immigration department says.
Taking questions from parliament's foreign affairs select committee about the government's repeated offer to accept 150 Australian-held asylum seekers, Immigration New Zealand (INZ) deputy chief Nigel Bickle said a full screening process would be conducted by New Zealand authorities.
"We have pretty well-developed processes about what we would do in the event that the Australians did take up the offer,'' he said.
The 150 people brought over from the centre in Papua New Guinea would be formally screened for health issues, security status and issues of criminality - a standard process for refugees - after ensuring they were in genuine need of protection.
That decision about need would be carried out in conjunction with the Papua New Guinean government and United Nations High Commissioner for Refugees
Based on public sources, about two-thirds of the about 400 people still in the island detention centre had provisionally been deemed as being in need of protection, Mr Bickle said.
He also reiterated earlier advice that the risk of people being smuggled into New Zealand had not increased as a result of Prime Minister Jacinda Ardern's persistent approaches to the Australian government.
"We have not seen any correlation between recent comments and increased activity, at this stage."
He said while smugglers were willing to use any public comments - from media or politicians - as propaganda, New Zealand's risk remained low due to its geographical position.
Based on leaks from Australian intelligence agencies, the National Party has been attacking Ms Ardern for last year repeatedly pressing the offer - which was initially proposed by the Key government in 2013.
Opposition MPs have cited reports describing criminality among detainees to question the danger they posed.
Others leaks said "chatter" by smugglers had increased since New Zealand's offer.
Australian politicians have also raised concerns the refugees could use New Zealand as a "back door" to get across the Tasman.
Mr Bickle was less than convinced by the argument, saying Australia was free to stop any of the asylum seekers if it wished.
"Every country has got the right to be in sovereign charge of their own borders," he said.
Under the government's proposal, the asylum seekers would come in under the regular annual refugee quota.