Andrea Mandell, USA TODAY

Cory Monteith, 31, died on Saturday at the Fairmont Pacific Rim hotel in downtown Vancouver.

"We are so saddened to confirm that the reports on the death of Cory Monteith are accurate. We are in shock and mourning this tragic loss," confirms his publicist, Melissa Kates, to USA TODAY.

Word began to spread on Twitter at roughly 1 a.m. ET that theGleestar had passed away due to an apparent drug overdose. CTV British Columbia, a local news station based in Vancouver, appeared to report the news first.

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Vancouver police said in a news conference on Saturday evening Monteith was found at noon on the hotel's 21st floor. He checked into the hotel on July 6, and was expected to check out on Saturday. When Monteith missed his checkout time at noon, hotel staff went to his room and found him.

"An autopsy is scheduled for Monday," said Vancouver Acting Police Chief Doug LePard. "The coroner will be determining the next steps with respect to establishing cause of death, but all indications are that there was no foul play."

Monteith voluntarilyadmitted himselfinto a rehab facility in March for substance addiction. In late April, the star completed the program and checked out. His last public outing was with his girlfriend andGleeco-star Lea Michele at the Chrysalis Butterfly Ball on June 8.

Monteith even joined in on theSharknadosocial media phenomenon on July 12, asking his 1.5 million followers what exactly "a Sharknado" was.

The actor shot to fame whenGleelaunched in 2009, playing lead hunk and football player-turned-warbler Finn Hudson.

Monteith toldParademagazine in 2011 he was "out of control" as a teen. He revealed that at age 13, he drank, smoked pot and skipped school in Victoria, British Columbia, after his parents divorced. By 16, he said, his drug use had escalated. He was "doing anything and everything, as much as possible." At 19, he entered rehab for the first time.

The actor had been dating Michele for more than a year. The two looked happy together at the June gala, and previously Michele issued a statement of support toPeoplewhen he entered rehab in April. "I love and support Cory and will stand by him through this. I am grateful and proud he made this decision," she told the magazine.

Michele's rep, Jillian Roscoe, issued this statement early Sunday: "We ask that everyone kindly respect Lea's privacy during this devastating time."

It is unclear when the couple was last together. Michele posted vacation pictures from a girls' trip to Cabo San Lucas on Twitter over the July 4 holiday. On July 1, she attended a Beyonce concert in L.A. and posted lyrics from one of singer's love songs,1 +1on her account, with a heart.

"I saw him a few weeks ago in NY, looking so happy. heartbreaking..." wrote Sophia Bush on Twitter.

TheGleecast, including Monteith, assembled as recently as June 28 to shoot promotional photos for the upcoming Season 5 of the Fox series. Adam Shankman, a frequentGleedirector, reacted the the news early Sunday morning.

"Goodbye my amazing and beautiful friend," wrote Shankman on Twitter. "The lights in my world just grew dimmer. The world just lost one of our best. I love u so much..." Kristin Chenoweth, who frequently guest-starred on the show, wrote, "RIP Cory Montieth. You will be loved. Always."

His co-star Mark Salling offered just one word via social media as the news broke.

It was simply "no."