Kiwis will soon face full-body scans at Australian airports or be banned from flying, in a radical security overhaul that could create greater airport delays.
The country's international airports will introduce the scanners in a A$28 million upgrade approved by privacy watchdogs.
The technology was trialled successfully in Sydney and Melbourne last year, but aviation experts are concerned its expanded use could create greater queues in air terminals.
New Zealanders make nearly a million trips across the Ditch a year for business and holidays, and flights there account for nearly half of our overseas travel.
Kiwis - and all other travellers - will face selection for the scans as they leave Australia.
NZ Transport Minister Gerry Brownlee said the efficacy of the technology was not yet known, and he would not rush to judgment before the scanners were rolled out in July.
He said New Zealand airports would not be following suit just yet.
"We have a different security profile to Australia's but we would be monitoring what happens once they do establish these things.
"Everyone would want to have as secure an arrangement as possible but it is a balance between super security and travel inconvenience as far as we're concerned."
Under federal laws introduced this week, any passenger selected for a full-body scan will have to comply. This closes a loophole which has allowed passengers to request a pat-down instead.
Only passengers with serious medical conditions will be exempted from the scans.
Australian Transport Minister Anthony Albanese says compulsory body scans are necessary to ensure the safety of airports.
"I think the public understands that we live in a world where there are threats to our security, and experience shows they want the peace of mind that comes with knowing government is doing all it can."
The government has assured travellers that they will not appear nude on screen; they will instead appear as a stick-like figure. This contrasts with some of the controversial scanners used in the United States, which show passengers with transparent clothing.
The government says the US-made scanners are the most sophisticated available, and will detect metallic and non-metallic items while emitting negligible radiation.
Mr Albanese said the strength of the scanners' radio signal would be similar to an average mobile phone call.
NZ aviation commentator Peter Clark said some of the scanners trialled in the US were time-consuming and had been criticised by passengers as overly intrusive, even if they did not show them as virtually naked.
"This now throws in another cost, another delay, another inconvenience to passengers. They're struggling with this in the United States because of the human rights aspect of it.
"I'm 100 per cent for safety and security, but how far do we go? Do we need to walk through the airport naked?"
Mr Clark said the plan seemed to go against recent initiatives to ease travel between Australia and New Zealand.
"Only last week we saw John Key with [Australian Prime Minister] Julia Gillard trying to get passport-free travel across the Tasman, and while this [law change] might mean people do not have to be profiled, it really does seem to contradict this initiative."
The scanners will be rolled out at international airports in Adelaide, Brisbane, Cairns, Gold Coast, Melbourne, Perth and Sydney.
New Zealand's international airports use security measures such as passenger profiling and depend less on scanners.
New Zealand and Australian passport holders, who are considered low risk, can bypass the luggage x-ray machines as they exit Customs.
If the full-body screening technology is ever introduced in New Zealand, Privacy Commissioner Marie Shroff has said extensive public consultation will need to take place beforehand.
A Unisys Security Index study showed that most New Zealanders would have no problem with full-body scanners at airports.
Two-thirds of respondents to the survey said they were happy to sacrifice some privacy for increased security.
* Passengers in Australian airports selected for a full-body scan will not be able to opt for a pat-down.
* Passengers will be prevented from boarding a flight if they refuse to be scanned.
* Only travellers with a serious medical condition are exempt.
* Will not show the passenger nude, but instead as a stick figure.
* Emit the same strength of radiowave as a mobile phone used from several metres away.
* Will discard the images once the passenger is cleared.