U.S.-listed shares of Canadian medical cannabis company Namaste Technologies Inc. NXTTF, +3.98% fell 20% in early trade Monday, after the company said it has fired its chief executive for cause and started a formal review of its strategic options. Toronto-based Namaste said it terminated Sean Dollinger after an investigation by a special committee of the board and removed him as director with immediate effect. The investigation was sparked by allegations made by an unnamed short seller. "The only one that was substantiated and required action, as recommended by the Special Committee, related to the sale of Namaste's US subsidiary, Dollinger Enterprises US Inc., in 2017, and subsequent transactions involving its assets and companies in which Sean Dollinger and Namaste's head of marketing David Hughes have a beneficial interest, as well as breaches of fiduciary duty by Sean Dollinger and evidence of self-dealing," the company said in a statement. Namaste has launched legal action against Dollinger for damages and disgorgement, said the statement. In the meantime, it has appointed Meni Morim as interim CEO. Morim has acted as chief product officer and director of AI since May of 2018, when it acquired Findify AB, a company that he co-founded and led as CEO. The strategic review comes after a recent expression of interest and may result in a sale of the company. Shares have gained 52% in 2019, while the ETFMG Alternative Harvest ETF MJ, +2.21% has gained 49% and the S&P 500 SPX, +1.05% has gained 8%.