(Legalise Cannabis Party website)

Medical cannabis has been legal in the state since 1996 while recreational cannabis was legalised in November 2016.

Mr Stronge says the tour is a unique opportunity for medical cannabis users to bring cannabis back into New Zealand legally.

"A doctor's evaluation and medical cannabis recommendation will be included as part of the package," he said.

Earlier this year when working for a client who uses medical marijuana, lawyer Sue Grey discovered a loophole in the New Zealand system.

"If the medicine was lawfully prescribed overseas and brought into the country into New Zealand and it's for medical purposes and it's one month's supply, then it's lawful. There is no offence under the misuse of drugs act," she said.

The Cannabis Party plans to use that loophole to allow tour members to bring the drugs back into New Zealand at the end of the trip.

The trips cost $4995 per person, including a return flight to San Francisco with Air New Zealand. No specific date for the tour has been given.

Newshub.