Police Minister Poto Williams has promised to release the latest gang numbers "in the coming days" as National MP Simeon Brown accuses her of "hiding" them.
Every two months the police compile the latest data for the National Gang List, and Brown formally requested the information from Williams' office two weeks ago - but he's still yet to receive a response.
"Either the numbers have increased significantly again or the Government is trying to covertly adjust the way they measure the number of gang members in New Zealand," Brown says.
"This deliberate attempt by the Police Minister to withhold the data shows that she and Labour do not want those numbers out in the public domain."
A spokesperson for the Police Minister told Newshub the latest gang numbers will be released in a matter of days and that the delay in responding to Brown wasn't intentional.
"This was an administrative error, and the numbers will be released in the coming days."
But Brown isn't buying it, telling Newshub it doesn't make sense that Williams' office has responded to his other requests.
"A very convenient response," Brown said. "I contacted her office on July 15 about responses to 19 questions which were overdue. She has responded to all of the others except this particular question."
The latest figures from May showed the number of gang members across New Zealand had passed 8000 for the first time, representing an increase of 2435 since Labour came to power at the end of 2017.
Brown, whose public criticism of the Mongrel Mob resulted in threats to his life, is calling for police to bring back Armed Response Teams (ARTs) - which were trialled last year and discontinued - to combat gang violence.
Violent criminal behaviour directed at police is ramping up like never before, according to Police Commissioner Andrew Coster. Police are also concerned about an increase in gun incidents and offenders being more willing to use them.
The Police Minister's refusal to back arming police over concerns for Māori and Pacific communities being targeted, has led to National leader Judith Collins calling on Prime Minister Jacinda Ardern to sack her.
"Labour makes the mistake of thinking they speak for all Māori and Pasifika people when they say they have listened to the 'communities'. No ethnic group is a monolith and in my electorate of Papakura I am hearing that my multi-cultural constituents support the police and want them to be able to sort out gang members.
"This cannot go on. Labour has to get real about crime and about empowering the police to do their job. This nonsense of making the police the 'bad guys' is creating a more tense and hostile environment which inevitably leads to more dangerous altercations."
It comes as the Government faces backlash for giving nearly $3 million in funding seized from Proceeds of Crime to a rehab programme linked to the Mongrel Mob.
Ardern said the scheme "showed signs of success".
"We have to make a decision in New Zealand - we either want to fund programmes that yes, will have people involved in them who have a criminal history but we are determined to address their methamphetamine addiction, or we exclude people with criminal histories from meth programmes.
"I for one want to stop victimisation and so that means we will be offering programmes to people who have a criminal past."