Hoods used to stop suspects and offenders from spitting at police officers belong in horror films and are cruel and degrading, a criminal justice advocacy group says.
Statistics released by police under the Official Information Act show the hoods were used 316 times between August 2014 and July 2016.
In just over a quarter of those times, the hoods were used on people who were 18 years old or younger.
The spitting hoods are a one-size item that slips over a person's head. The top half is made out of dark mesh while the lower part is a white sheet that prevents spitting.
Considerable force by a number of officers might be required to put a hood on, the police said.
Officers must get permission before using a hood and a person wearing a hood must be constantly monitored.
JustSpeak director Katie Bruce said the hoods had no place in modern policing and New Zealand should stop using them immediately.
"I was surprised at the extent that they're being used, especially against young people, when we know that it's really important that young people have positive experiences with police," Dr Bruce said.
"There are also vulnerable adults such as those with mental health issues who this would be particularly distressing [for]."
Dr Bruce said the hoods were more likely to be used as a punishment than a deterrent.
"They're kept in police cars so they're not available at the time when police might need them. And if they're not preventing spitting, there's actually no reason to use them."
Other police forces used safety goggles instead of putting hoods over offenders, Dr Bruce said.
In the last two years, at least 900 officers were spat at - although police said that figure would not include all incidents, as it only included officers who were required to use force.
Labour police spokesperson Stuart Nash said spitting at an officer was assault, and police needed to feel protected.
"For me it's all about police safety, there's no doubt about that. If these grubby buggers are going to spit at police, we need to do something to ensure police don't catch hepatitis or anything like this," he said.
International scrutiny
Alleged abuse of teenage boys at an Australian youth justice facility in the Northern Territory, including the use of spit hoods, prompted the state's government to launch a Royal Commission of Inquiry earlier this year.
The hoods have also come under scrutiny in London, where officers started using them this month.
Amnesty International UK warned the hoods could restrict breathing and create disorientation, and could be dangerous.
Police Minister Judith Collins said she was confident police in New Zealand were using the hoods appropriately.
Police said the spitting hood was considered an intrusive mechanical restraint and a supervisor's authority must be obtained before the hood was used - unless a supervisor was not available and immediate action was required to prevent the person spitting.
A person wearing a hood must be constantly monitored and it should not be used on anyone vomiting, having difficulty breathing, or bleeding profusely from the mouth and nose, police said.