The TV star had faced addition problems since has late
Cory Monteith, star of the hit TV musical comedy Glee, died from a heroin and alcohol overdose, a coroner in British Columbia has announced.
The 31-year-old Canadian actor, who played Finn Hudson in the Fox TV hit, was found dead in a Vancouver hotel room on Saturday.
Monteith, who had been in the musical comedy since its 2009 start, was treated for drug addiction in April.
Fox TV officials had described Monteith as "an exceptional talent".
In a statement, the coroner's office said: "There is no evidence to suggest Mr Monteith's death was anything other than a most tragic accident."
It said a post-mortem examination had determined "a mixed-drug toxicity involving heroin and alcohol" was the cause of death.
Monteith is thought to have been alone when he died because video footage and other evidence suggested he returned to his room at the city centre Pacific Rim Hotel by himself after spending time with other people earlier.
The alarm was raised when he failed to check out at midday on 13 July. He had been staying at the hotel for a week.
Monteith had previously talked frankly about struggling with addiction since he was a teenager.
He was treated for drug abuse aged 19 and later told one interviewer he took "anything and everything".
Girlfriend Lea Michele issued a statement saying she loved and supported Cory when he entered rehab last April.
Michele played Monteith's opposite number Rachel Berry in Glee, which follows a group of American secondary school misfits in Ohio who form the glee club in their quest for singing contest glory.
As Hudson, Monteith played the school's star quarterback who risks alienation by his friends after joining the club.
Known for its melodic covers and celebrity cameo appearances, Glee's four series had made global celebrities of its cast. The show featured guest spots by Britney Spears, Gwyneth Paltrow and Neil Patrick Harris.
Singer Taylor Swift - who briefly dated Monteith in 2010 - led tributes on Sunday, writing on Twitter: "Speechless. And for the worst reason."
Rihanna tweeted: "Cory Monteith, may your spirit be at peace, and may you fly with the angels... Heartbreaking, my prayers are with all of his loved ones!"
Veteran actress Mia Farrow added: "Rest in peace Cory Monteith. Sad, very very sad."
A host of his Glee co-stars joined the tributes.
"How sad to read about Cory Monteith passing away. What a shame. He was a lovely, kind, talented guy and will be missed," wrote Neil Patrick Harris, who won an Emmy for his guest role on the show.
"RIP Cory Monteith," wrote fellow guest star Kristin Chenoweth. "You will be loved. Always."