The police are refusing to provide more details about any plans to expand the use of weapons that fire sponge-capped bullets.
The weapons are designed to be non-lethal but have sparked outrage in the US where the police have fired them at Black Lives Matter protesters,causing serious injuries.
Armed Offenders Squads nationwide have had access to the weapons that fire sponge rounds since 2015.
The large 40mm rounds are capped with sponge and cannot penetrate the body. They are fired from a gas launcher with a range of about 30m.
Lance Burdett, who spent more than a decade as a crisis negotiator working alongside the Armed Offenders Squad, said they were most effective being used against a solo offender.
"Where you want to take the person down [but] it is too dangerous to do so because of what they've got, they might have a weapon or a sword something like that.
"You can't get close because the person may run at you, [it's] too far away to deploy the taser, too far away to use [pepper spray].
Police Commissioner Andrew Coster. Photo / Mark Mitchell
"So therefore I would see them being a very valuable tool."
But Victoria University criminologist Trevor Bradley said they could cause serious injury.
"If you're hit in the facial area, or if you are hit around the groin or the crotch area it could cause a lot of damage."
Police Commissioner Andrew Coster floated the possibility of an expanded use of the weapons on Morning Report the day after a trial of mobile armed police teams was scrapped.
Coster cited the use of sponge round weapons during the trial as an example of a "less-lethal option" the police used to "de-escalate" situations.
However, it is not clear in documents about the trial that the weapons were ever used.
The Armed Response Teams (ART) were fiercely criticised for poor record-keeping, a lack of community consultation, and that they would disproportionately target Māori and Pacifica communities.
University of Waikato criminologist Juan Tauri said in raising the use of the weapons the police commissioner was possibly trying to divert attention from the public outcry at the ARTs.
But he said this diversion backfired because everyone can see the carnage the weapons are wreaking in the hands of US police on peaceful protesters at Black Lives Matter marches.
"We've seen pictures of people who have lost eyes, there've been reports of mashed teeth, broken jaws, concussions from this weapon.
"I'm just really wondering who is doing the media strategy for the police at the moment when they are promoting this so-called non-lethal round when we're seeing how damaging it can be."
Police Minister Stuart Nash. Photo / Mark Tantrum)
Tauri says inevitably these kinds of weapons would be used disproportionately against young Māori and Pacific people.
If the weapons were rolled out it would show the creep towards the militarisation of New Zealand police, he said.
Bradley said he feared the more comfortable police got using the weapons the more likely they would be to reach for them too often and in inappropriate circumstances.
"One would hope that police would use these very infrequently, if at all really.
The police would not answer RNZ's questions about how the weapons could be used by officers in the future.
But they said in a statement that the Armed Offenders Squad and Special Tactics Group would continue to use the weapons, and it is an option that "will be considered as part of the work being undertaken into our broad tactical capability".
RNZ asked Police Minister Stuart Nash if there were plans for police to expand the use of the weapons and was told in a statement that "no such proposal is in front of the minister, and he would expect to be consulted if there was such a proposal in the future".
