CannTrust Holdings Inc. ctst ca:trst said late Thursday that it has ceased sale and shipment of all cannabis products, days after the company said Health Canada inspections revealed the existence of several illegal grow rooms at an Ontario facility. Health Canada seized more than five metric tons of CannTrust's inventory. CannTrust's U.S.-traded shares nearly 10% in the extended session Thursday. The company also said it planned to form an independent special committee to investigate the illegal grow rooms "in its entirety." Beyond the unlicensed grow rooms, earlier this week one of its Danish export partners discovered that it sold some of the illegal pot CannTrust grew and exported, which is an indictable offense. Before Thursday's after-hours trading, the stock's week-to-date losses were more than 40%. It closed down 1.9% during regular trading.