'Simply not true': Expert says claims of exploding gang numbers 'heavily inflated'

Figures showing an explosion in New Zealand gang numbers over the past three years are likely "heavily inflated", a gang expert says.

Gang numbers have increased by 46 percent since Labour took office in 2017, according to figures released by the National Party earlier this week - up to 7800 from 5300.

"This Government is soft on crime," National leader Judith Collins said on Wednesday.

But Jarrod Gilbert, a sociologist and New Zealand gangs expert, said there are issues with the way gang numbers are calculated.

"The problem we've got - it's a methodological issue," he told The AM Show. "What it is, is a problem with how those numbers are collected.

"It's incredibly easy to get on the [gang] list because the police identify someone wearing a patch and so their name goes onto this database. But if people leave the gangs - and so many people are - it's very, very hard for police on the street to identify when someone's left."

Gilbert, also the author of Patched: The History of Gangs in New Zealand, said that causes the figures to spike.

"They don't correspondingly fall in the same way," he told host Duncan Garner. "Without question, those numbers are really heavily inflated so when we hear things like, 'the gang numbers have doubled in Wellington in the last three years,' it's simply not true."

He said while there has been some growth in the gang scene, some gangs are now handing out patches more quickly.

"What that means is easy come, easy go. So you're seeing a lot of people join, realise it's not for them whatever reason, then dropping off."

Gilbert is disappointed in recent comments by politicians about gangs.

"I get nervous when politicians are starting to create policy formation on what is really poor data that isn't fit for that purpose," he said.

Last week, Operation Tauwhiro was announced by Police Commissioner Andrew Coster - what he said is a "nationwide operation to disrupt and prevent firearm-related violence by criminal gangs and organised crime groups".

In response to the announcement, National MP Simon Bridges described Coster as a "wokester". 

"With this softly softly [sic] approach from our wokester commissioner, expect gang and gun violence to continue to worsen," Bridges wrote on Twitter.