The 31-year-old "Glee" star was found dead in his room at the Fairmont Pacific Rim Hotel Saturday afternoon.
Police said Monteith was due to check out of the hotel Saturday, where he had been staying since July 6. When he missed his noon checkout time, hotel staff went to his room and found him.
A coroner said Monteith had been dead for several hours when his body was found. While he was with other people Friday night, video footage showed him returning to his hotel room alone. Police do not believe foul play was involved.
Police have not officially determined a cause of death.
Born in Calgary, Canada, Monteith had a history of substance abuse and checked himself into a treatment program earlier this year. He had previously checked into rehab when he was 19.