(CNN) -- Medical examiners will conduct an autopsy Monday on "Glee" actor Cory Monteith.
Staffers at the Fairmont Pacific Rim Hotel in Vancouver, Canada, discovered the 31-year-old actor's body in his hotel room Saturday after he missed his checkout time, police said.
"The coroner's service has decided that we will conduct an autopsy and toxicology testing on Cory to make sure that we do have the best possible information to determine the cause of death," B.C. Coroner's Service spokeswoman Barbara McLintock said Monday.
While the cause of death was not immediately apparent, police have ruled out the possibility of foul play.
Monteith had been public about his struggle with addiction and checked into a rehab facility in late March.
"It's all about perseverance. Absolute perseverance. You can always get back up," he told Glamour magazine in June.
It was his second stint in a treatment facility.
Monteith played Finn in the popular Fox series, and credited "Glee's" success with helping him to turn his life around.
"It always blows my mind to think about how it was just a Fox pilot that started so humbly a couple of years ago" the actor told GoldDerby in June 2012.
The Facebook page RIP Cory Monteith had more than 669,000 likes early Monday morning, an indication of how popular the actor was with fans of the show.
The "Glee" staff released a statement via Twitter early Sunday morning, saying, "We are deeply saddened by this tragic news. Cory was an exceptional talent and an even more exceptional person."
Monteith's on- and off-screen girlfriend Lea Michele, who plays Rachel Berry on the show, has not yet released a statement.
Her representatives asked Sunday "that everyone kindly respect Lea's privacy during this devastating time." The statement added that the actress was "devastated" by the news.
The couple had been dating for more than a year.
In April, Michele voiced her support for Monteith's decision to enter rehab, telling People magazine. "I love and support Cory and will stand by him through this."
Adam Shankman, who directed an episode of "Glee" for each of the past three seasons, told CNN's Poppy Harlow that he had talked to Monteith on Saturday morning.
Shankman said Monteith was the glue of "Glee."
"I had several interactions with him (Saturday) where he said that he was doing amazing," Shankman said. "He even said I am feeling fantastic. I'm like everybody else, really devastated and confused by what happened."