A Waikato law professor says 3D-printed firearms are not yet a threat to New Zealand, but could be as technology evolves.
Police in New Zealand are monitoring developments around the firearms, which are assembled from plastic parts that can be made with a 3D printer.
A court in the United States yesterday blocked moves for the online release of plans on how to make a 3D-printed gun.
That would allow anyone with the right machine and materials to produce an untraceable gun at home.
Alexander Gillespie of Waikato University, who has specialist knowledge in firearms laws, said it was a low-risk scenario right now.
"The ones we're seeing, if they're done with cheap technology, are probably more of a risk to the person trying to assemble it than the actual person it could be pointed at."
Professor Gillespie said the difficulty could be when people had access to the right technology, because they would then be able to assemble something that they could not buy lawfully.
But at the moment the technology needed to print in 3D was hugely expensive.
Professor Gillespie said in terms of the law, New Zealand was on the back foot as much as anyone, except Australia.
New South Wales is outlawing blueprints for making guns, which means possessing the plans on a cloud service would be a criminal offence.
"New South Wales has foreseen this, but Australia is very much the foremost leader in the world probably, on gun regulation. They're always scanning the horizon, but a lot of countries right now will be playing catch-up," Prof Gillespie said.
He said said New Zealand would need to look overseas for examples of best practice on how to legislate for change.
Police Minister Stuart Nash said the police were "very aware of developments" and would continue to monitor the New Zealand situation closely.
"Our firearms regime is different to that in the US but nevertheless we are obliged to keep ahead of technology," Mr Nash said.
He said the Arms Act required anyone in possession of a firearm to have a firearms licence or endorsement, or be under the immediate supervision of a licence holder.
"This is a new field for law enforcement and if police believe legislative or regulatory change is required, I expect them to advise me of the best course of action."
He said anyone unlawfully in possession of a 3D firearm could expect to face the consequences of the law.
Professor Gillespie said 3D printable weapons would be a challenging area to police because it would involve not only firearms, but the internet also.
But a starting point would be the type of penalty needed for a non-licensed person in possession of a firearm.
Prof Gillespie said there were easier ways to get firearms than making them; lawful people purchased them while others got them through the black market.
And right now, there were worse things on the internet.
"You shouldn't just see it in isolation of firearms - you should see it in relation to other threats on the internet, like how there's capacity to make bombs, and how you've got people who put recipes up there on how to make very nasty things that can do a lot of terrorist-like damage.
"They need to all be put in the same basket and treated equally."