A judge has described the importation of 12 cannabis seed from Canada by a Marlborough man as "very unusual".

Steven Craig Shirley, 60, of Tuamarina, appeared at the Blenheim District Court on Monday charged with importing cannabis seeds, a class C drug, for personal pain relief.

Shirley admitted to police when arrested he intended to grow the seeds and use the cannabis for his own use to relieve a painful shoulder injury suffered five years ago in a motorcycle accident from which he "escaped death", the court heard.

Shirley had severe health and sleep issues caused by the pain and could not afford to buy cannabis in New Zealand.

He was unable to have an operation on the shoulder and needed a particular type of cannabis to help with the pain, the court heard.

Between June 1 and August 8 this year, Shirley, with the help of his partner, used the internet to order 12 cannabis seeds from the 'Mary Jane Seed Barn' website.

The seeds were taped inside the lid of a box of false eye lashes labelled 'Nu Age Beauty Supplies'.

The box was posted from Canada and intercepted by Customs at Auckland International Airport on August 10.

In sentencing, Judge Ian Mill said the case was "very unusual given the amount of cannabis already growing" in New Zealand, and because only 12 seeds were imported.

"It is not your normal importation case," he said.

Judge Mill told Shirley the charges carried a maximum penalty of eight years in prison.

"You were playing with fire without actually knowing it."

Shirley was convicted and sentenced to 100 hours' community work.