Kenneth Carrington is on trial in the Palmerston North District Court, accused of arson.

A cannabis grower forced to forfeit a house to the Crown is accused of torching the property after leaving crude graffiti on the walls to taunt police.

Several emails were also sent to police from Kenneth William Earnest Carrington, with one declaring "Woodville is yours, or what is left of it".

Carrington is on trial in the Palmerston North District Court, charged with the arson of a Woodville property in February 2017.

Prosecutor Truc Tran​ told Judge Lance Rowe, who is hearing the case alone, on Monday the evidence was circumstantial.

Carrington pleaded guilty to cultivating and possessing cannabis for supply, and was sentenced to home detention.

Police then launched an investigation into any potential proceeds of crime from Carrington's offending, which they could apply to seize on behalf of the Crown.

A property on the outskirts of Woodville where Carrington grew the drugs was subject to a forfeit order.

Detective Sergeant Sonya Douglas, who took part in the proceeds investigation, said Carrington sent her multiple emails - many of them unhelpful.

Two emails sent in quick succession said "bollocks to you", while another said "f... you, I hope you get cancer", Douglas said.

A colleague sent her images a few weeks later of the Woodville property, which had been vandalised. Windows were smashed out and there was graffiti on the walls.

The graffiti said things like "enjoy your victory", "I grew dope for 13 years" and "f... you Sonya Douglas", she said.

The trial was also played phone conversations with Meridian Energy, during which Carrington organised for power to the house to be disconnected.

There was a fire at the property before the alleged arson.

Steve Peretini​, the deputy chief of the Woodville fire brigade at the time, said he went to the property in August 2016 to find a bus on fire.

Carrington told him the blaze was started by grinding equipment, and that he had it under control with a garden hose.

He initially refused to let firefighters put it out, but relented when police arrived, Peretini said.

On the day of the alleged arson, Stephen Fiveash was driving his ute from Woodville to Pahiatua to cut up firewood.

He said he was stopped at some roadworks outside the house in question, and saw a red Mitsubishi Pajero stationary in the driveway.

But defence lawyer Steve Winter put to Fiveash that his evidence had changed, because in a police statement he said the driver of the Pajero was looking to turn into traffic.

Fiveash said the Pajero was "sitting" in the driveway.

"The car was parked."

When opening the case, Tran said someone was spotted driving a Pajero around Woodville with equipment in it.

A search of Carrington's address after the arson found that equipment.

Winter, in response, said the case was about reaching the correct standard of proof.

"I accept you have plenty to be suspicious about," he told the judge.

The trial will likely finish on Tuesday.