The statement of claim alleges Organigram breached its contract with customers to provide a certified organic product free from unauthorized pesticides. It also alleges the company was negligent in the design, development, testing, manufacturing, distribution, sale and marketing of its products.

Lawyer Ray Wagner said Organigram originally offered a refund to customers, but later reversed its position and offered credit for future purchases. The company has estimated the value of credits to be more than $2 million.

Wagner said receiving credits for the products is not enough, especially since there are customers who do not intend to purchase Organigram products again.

"We want the return of the funds that people paid for the product," said Wagner in an interview Monday. "The product was not as it was billed. It was billed as an organic product... and we want our money refunded."

Wagner said the proposed representative plaintiff — writer Dawn Rae Downton — consumed the cannabis for eight months for her inflammatory arthritis before learning she was being exposed to unapproved pesticides.

She suffered health problems including nausea and vomiting — symptoms that improved one month after she stopped using the product, according to the lawsuit.

Health Canada said there are 13 approved pest control products for use on marijuana. It said last month it was conducting random testing of cannabis products produced by licensed producers in response to recent recalls.

Last year, Mettrum Health Corp. recalled medical cannabis products that were exposed to a foliar plant spray.

The proposed class-action against Organigram, filed Friday, has not yet been certified.

Organigram announced earlier this month that Greg Engel would be taking over the role of CEO on March 13. Current CEO Denis Arsenault will move up to a newly created executive chairman position.

— By Aly Thomson in Halifax.

By The Canadian Press