A man who tried to eat his methamphetamine stash while police searched him has been ordered to attend treatment to address his dependency issues.

Harley Allan Mathieson, 31, arrived home on November 23 to find police executing a search warrant at his Dunedin home.

He got back in the car to leave but was ordered to remain at the scene.

As he was being searched, Mathieson grabbed a plastic bag from the vehicle, thrust it into his mouth and tried to swallow it.

Police intervened and the defendant spat out the package, which contained a small amount of the class A drug.

A search of his car turned up a pipe for smoking the methamphetamine, digital scales and a pocket knife.

Mathieson subsequently pleaded guilty to possession of the drug, the pipe, the weapon and wilful obstruction of the police officer.

He was also sentenced on a charge of vehicle conversion, from a month earlier, which had prompted the police visit to his home.

On the night of October 20, Mathieson and partner Mindy Johnston picked up Dean Corvette Eric Webber from Brighton and took him to General Tyres Ltd where he worked.

The duo dropped Webber off near the South Dunedin business and waited.

Their co-offender, who had memorised the access codes to the premises got in and spent some time moving vehicles around the workshop so he could get to a jet ski - worth more than $50,000 - stored in a back room.

After putting it on a trailer and hitching that to a work vehicle, he drove out to the forecourt and replaced all the other vehicles inside the property.

The trio then travelled in convoy to Green Island before piling in with Webber and heading north.

Using fake names, they boarded the ferry over Cook Strait, the court heard, and the jet ski was eventually sold to a mystery buyer.

Johnston was also charged with conversion and she and Mathieson came before the Dunedin District Court last week.

They tearfully embraced in the dock - Mathieson had spent four months in custody because he continually breached his bail by contacting Johnston.

Judge Michael Crosbie noted neither defendant had an extensive criminal record.

Mathieson was sentenced to 12 months intensive supervision and 250 hours' community work, while Johnston received the same term of rehabilitative oversight with 120 hours' community work.

Webber was previously jailed for two years nine months.