"We don't have the information right now if he was driving while intoxicated with alcohol or drugs," said police Constable Manuel Couture. "But we seized an amount of drugs on him. It was marijuana, and he is going to be accused of drug possession."
The 19-year-old driver is also expected to face charges of dangerous driving causing death and criminal negligence causing death.
Police spokesman Manuel Couture said the man was also behind the wheel with a suspended driver's licence.
Two men, aged 18 and 19, died in the crash. Three others were seriously injured, but are expected to survive.