Paul Stevenson was on home detention for a drink-drive charge when the police turned up in February to search his house.

It was then they found four cannabis plants, up to a metre tall, plus 464 grams of cannabis stuffed in a bag, in an armchair.

The Nelson man with previous convictions for drug-related offending told police it was for his own medicinal use.

Defence lawyer Mark Dollimore told the Nelson District Court today that Stevenson had a documented condition that caused "serious pain", and that he had used cannabis extensively for some time to manage it.

He had tried buying legitimate medicinal cannabis products but at $350 a bottle the cost had placed it out of his reach financially.

Medical cannabis is legal in New Zealand with a doctor's prescription.

Legislation introduced in 2017 created a pathway to develop a medicinal cannabis industry in New Zealand and to make products more accessible. Regulations to support the Bill came into force in April 2020.

The New Zealand Drug Foundation, which has been working for many years to improve access to medicinal cannabis, said despite a move in the right direction, products remained inaccessible to the vast majority of New Zealanders who needed them, because of the excessive cost of the unsubsidised product.

Dollimore explained to the court that Stevenson was on home detention on a drink-drive matter, which included post-release conditions.

He said Stevenson was not lazy and wanted to work, but because of his pain he was unable to do community work.

Judge David Ruth acknowledged Stevenson's criminal history, and said in sentencing him he accepted the need for cannabis-based medicine was genuine, but as the law stood, "if you do it yourself, this is where you'll end up".

Stevenson was fined $300 plus court costs on the charge of possession, and $500 on the charge of cultivation. An order was made for the destruction of the plants.

- Tracy Neal, Open Justice