The cause of "Glee" actor Cory Monteith's death remained unclear Monday, and authorities in Canada said it could take several days before toxicology test results are in.
RELATED: Stars react to Cory's death
Vancouver police Sgt. Randy Fincham said there's nothing to indicate the death was due to illicit drug use.
Monteith, 31, was found dead in his Vancouver, British Columbia, hotel room on Saturday, according to police, who have ruled out foul play.
Police said Monteith had been out with people earlier, but video and electronic records from the hotel indicated he returned to his room by himself early Saturday. He was believed to be alone when he died.
Monteith's passing recalls the lives of Heath Ledger, Corey Haim and River Phoenix -- actors who battled substance abuse and died in their 20s and 30s. Monteith talked bluntly about struggling with addiction since he was a teenager, calling it a serious problem and telling Parade magazine in 2011 he was "lucky to be alive."
Monteith admitted himself to a treatment facility in April for substance addiction and asked for privacy as he took steps toward recovery, a representative said at the time. Lea Michele, Monteith's "Glee" co-star and real-life girlfriend, told People magazine that she loved and supported him and was proud he was seeking help. It was not Monteith's first time in rehab. He also received treatment when he was 19.
The FOX network and the producers of "Glee," including 20th Century FOX Television, called Monteith an exceptional performer "and an even more exceptional person." Michele asked for privacy upon hearing the news of his death.
A makeshift memorial emerged outside the Vancouver hotel. #RipCoryMonteith and #StayStrongLea became trending topics on Twitter.
In England, what was supposed to be a weekend celebration of "Glee" turned into an impromptu memorial after news of Monteith's death rocked a fan convention.
"The news was devastating. No one had any idea what to say or do," said Chloe Harvey, an 18-year-old fan from Portsmouth, England. "It just shows how much of a truly amazing guy Cory was that everyone was so shocked and emotional about the news."
"Glee," with its catchy song-and-dance numbers and high-profile guest stars, like Gwyneth Paltrow and Britney Spears, became an instant hit when it debuted in 2009 and made celebrities of Monteith and the rest of the relatively unknown cast.
Monteith served as the show's resident hunk with a heart of gold. He played Finn Hudson, a football quarterback with two left feet who found more camaraderie in the choir room than on the football field. After his character graduated high school, Hudson sought to find himself before settling on what he wanted to do with his life: become a teacher and mentor.