Ban on public display of gang insignia is part of a wider crackdown on gangs that some experts say could infringe on rights while doing nothing to cut gang membership

New Zealand’s gangs will need to hide their gang patches or face prosecution after a new law banning gang insignia in public came into force on Thursday – a move critics believe could risk breaching the Bill of Rights and do little to reduce gang membership.

At midnight, it became illegal for gang members to display signs, symbols or patches – large insignia sewn on to jackets, for example – anywhere in public. This includes displaying insignia on their clothing or vehicles.

Breaches of the ban carry a sentence of up to six months imprisonment or a $5,000 fine, and insignia would have to be forfeited and destroyed.

Three minutes after the ban came into effect, a Mongrel Mob member based in Hastings was arrested for displaying a large Mongrel Mob sign on the dashboard of his car, the police confirmed to the Guardian. He was issued a summons to appear in court and the sign was confiscated, police said.

“The free ride for gangs is over,” said Paul Goldsmith, the minister for justice. “Gangs in our country think they’re above the law and can choose which laws they comply with, and this government does not accept that.”

The ban forms part of the government’s wider “crackdown” on gangs, including non-consorting orders and police being given the power to stop gangs from associating and communicating.

Greater weight will also be given to gang membership at sentencing, enabling courts to impose more severe punishments, Goldsmith said.

Those who have been prosecuted for breaching the gang patch ban three times will also be banned from wearing the patch at home, and police will have increased powers to search homes if they suspect members still have insignia.

Police have been meeting with gangs ahead of the law changes and said they will actively enforce any breaches.

“Gangs are well aware that once this law comes into effect, they are not allowed to wear a gang patch in public,” said Paul Basham, assistant commissioner and controller of the nationwide operation to enforce the law.

“If we come across anyone wearing gang insignia in public, we won’t be taking the excuse of ignorance as a defence.”

Gangs have existed for decades in New Zealand and hold a complex space in society: while they can be linked to violence and crime, they can also act as forces for good within their communities. Police figures provided to the Guardian puts membership at roughly 9,384.

Members of the country’s largest gang, the Mongrel Mob, are a familiar sight in many provincial towns and cities, and it is common for members to have insignia, including bulldogs, tattooed on their faces. Tattoos and coloured clothing have been excluded from the ban.

Black Power gang life member and community advocate, Denis O’Reilly, told RNZ there will be a “spectrum of response” from gang members to the law changes, including resistance.

“The main advice gang leaders are providing their members is that of Minister Goldsmith’s: don’t get caught,” he said. “But in the main, I think people will use subterfuge, they’ll wear patches inside out, they’ll wear cloaks…to try and get around the law.”

Mongrel Mob members who held a meeting on Wednesday in Ōpōtiki, in the North Island’s Bay of Plenty region, told Stuff many would not surrender their patches.

“We’re all backing one another on this, we’re all together on this. We die for our patch. We’ve said that forever, from day one.”

Others said the ban was a human rights issue: “it’s taking away our freedom. I don’t go tell [you] what to wear.”

Critics of the ban say the legislation is vague and could risk infringing the Bill of Rights, while doing nothing to alter gang membership.

In an open letter to Goldsmith in August, the Law Society said the law allowing authorities to search homes for insignia was an “incursion into private life” that could raise Bill of Rights concerns.

The society said the law could result in a person being held criminally liable for being proximate to someone in possession of gang insignia, while the definition of gang insignia could – when taken literally – include “printed reproductions of gang insignia, making it a criminal offence to possess a newspaper with a gang symbol in it, or certain books”.

“The residential ban could extend to insignia never intended to be displayed in public – such as a gang member having their father or grandfather’s patch as a memento,” it said.

Labour leader Chris Hipkins told media it was unlikely the law changes would lead to a reduction in gangs.

“This is a measure by the government to look tough on crime. The reality here is it is not going to lead to one single person leaving a gang.”