Representatives for Canopy and Alantra declined to comment. GHO didn't respond to requests for comment.

Alcaliber is majority-owned by Spanish billionaire Juan Abello's investment fund Torreal SA, with French drugmaker Sanofi also holding a 40 percent stake. Founded in 1973, it supplies narcotic raw materials based on the cultivation of the opium poppy and its transformation into poppy straw, as well as the extraction of alkaloids, according to the owner's website. A representative for Torreal also declined to comment.

Canopy counts more than half a million square feet of indoor and greenhouse production capacity, according to its website. Last year, alcohol giant Constellation Brands Inc. bought about 10 percent of the company, becoming its biggest shareholder.