"At this point there is no evidence to suggest Mr. Monteith's death was anything other than a most-tragic accident," the BC Coroners Service says in a statement released Tuesday.
Police spokesman Constable Brian Montague said, "There was evidence in the room that was consistent with a drug overdose."
He did not reveal what that evidence was, but that it was believed Monteith was alone when he died. The actor had been out earlier with three other people. Their identities were not revealed but Montague said they were two women and a man.
The cause of the Glee star's death at age 31 was determined by an autopsy and toxicology tests. An investigation by the coroner continues, but Montague said the police portion of the investigation is completed.
"Mr. Monteith's family has been made aware of the circumstances surrounding the death," the Coroners Service says. "On behalf of family members, the BC Coroners Service asks that the media respect their privacy at this difficult time."
The Canadian native completed a month-long stint in a treatment facility for substance addiction in April and had been open about his lifelong struggles with substance abuse.
It's still unclear what happened after Monteith arrived in Canada and checked into the Fairmont Pacific Rim on July 6. He and his manager dined on Thursday night with Maureen Webb, the co-founder of Project Limelight Society, who said the actor "looked so good, so healthy."
Police say that the next night, Monteith and the three people left his hotel room and that the actor returned alone at about 2:15 a.m. Saturday. A hotel staff person found his body shortly after noon when Monteith didn't check out.
Fans of Monteith's may make donations in his name to three charities that were especially important to him: Project Limelight Society, which exposes youth living in Vancouver's Downtown Eastside to the arts; Virgin Unite, founded to support entrepreneurial efforts to better the world; and Chrysalis, which helps homeless and low-income individuals find employment.