Police Minister Stuart Nash is backing police aerial drops to destroy cannabis crops, which medicinal cannabis advocates say is denying hundreds of sick people vital relief.
Advocates and growers say more than 1000 plants were poisoned in drops over Northland and west Auckland last month.
The Government passed a law last year that gave people in palliative care a legal defence to use cannabis for medical reasons.
It has until the end of the year to put in place a regulatory regime for medicinal cannabis, but in the meantime it is still illegal to supply cannabis for medicinal use without Ministry of Health approval.
Medicinal Cannabis Awareness co-ordinator Shane Le Brun said the new legal defence has helped 25,000 patients, but legal products cost about $800 a month and patients often relied on cheaper - but illegal - means of supply.
He said police were destroying outdoor crops of anything more than half a dozen plants, but those were not all for commercial purposes.
"With the referendum [on legalising recreational cannabis use next year], it feels like police are having a last hurrah. But this is affecting real people with real needs."
But Nash backed the police.
"At the moment, if you're growing cannabis in a quantity that the police think is commercial, then you are breaking the law."
He said medicinal cannabis advocates who said medicinal crops were being destroyed were being "a little bit disingenuous".
"My understanding is that police are going after crops that are of a commercial scale, and I would expect them to."
He said police would use discretion when it came to medicinal cannabis use until the Government's regulatory regime was in place.
Auckland Patients Group leader Pearl Schomburg, who has long advocated for medicinal cannabis, said Nash was "completely out of touch".
"How would he know they are commercial crops? Are they flagged in the backyard? These are primarily small grows being used for medicinal purposes.
"The Police Minister is being disingenuous if he thinks he has the knowledge that those were all commercial grows. He's dreaming."
Asked if she knew anyone whose supply of medicinal cannabis had been cut off after the police aerial drops, she said: "Yes. I cannot have any more medicinal cannabis from my grower because of that raid."
She listed a range of issues she suffered from including rheumatoid arthritis, peptic ulcers, and surgical injuries to her shoulders and feet.
"I'm in chronic pain on a daily basis."
Schomburg has posted photos on Facebook of a grower - known as Gandalf - who had lost 50 plants that would have helped several patients, including 8-year-old Charlie McKendry, who had a brain tumour when he was very young.
"For children like Charlie, when you take away that primary medicine to help them settle and be stable, you're going to potentially send them into a nosedive," Schomburg said.
A police spokesperson did not answer whether police distinguished between commercial and non-commercial grows for aerial drops.
The only legal way to supply medicinal cannabis was through a licence issued by the Ministry of Health.
"All other cultivation of cannabis, at either a personal or commercial scale, is not legally permitted," the spokesperson said in a statement.
"Organised criminals continue to make money off supplying cannabis to our communities. Therefore, police will continue to target and disrupt the supply chain to prevent them profiting. This includes the use of aircraft to identify illegal cannabis grows."
A total number of plants destroyed was not available at this stage as the aerial operation was ongoing, the spokesperson said.