Glee star Cory Monteith died of a fatal cocktail of heroin and alcohol, a coroner's report has concluded.
The 31-year-old star, who played Finn Hudson on the hit TV show, was found dead in a Vancouver hotel in July.
Investigators at the scene found drug paraphernalia, including "a spoon with drug residue and a used hypodermic needle, along with two empty champagne bottles and multiple glasses".
Coroner Claire Thompson concluded that Monteith's death was "accidental".
The final findings support the initial coroner's report into the death of the Canadian actor on 13 July.
At the time of his death, Monteith had an alcohol level of 0.13 percent, with a "moderate" level of intoxication. The report also pointed to the presence of morphine, codeine and "6-monoacetylmorphine," a by-product of heroin.
Hotel video footage showed the actor returning alone to his room in the early hours of 13 July, marking the final time he was seen alive.
"He had checked in to the hotel on July 6 and had been expected to check out on the 13th," the report stated. "When he had not done so, hotel staff checked his room and found him unresponsive on the floor."
The report concluded the actor had been dead for several hours: "Mr Monteith was clearly deceased and resuscitation was not attempted."
Monteith, who had been in Glee since its inception in 2009, was admitted to rehab earlier this year having struggled with addiction since he was a teenager. The coroner's report said the actor's "periods of abstinence ranged from years to months in duration".
The report found that his erratic drug use contributed to his death, adding that "after a period of cessation from opiod drug use, a previously tolerated drug concentration level may become toxic and fatal".
Glee, which follows a group of American high school misfits who form a singing club, will pay tribute to Monteith in a special episode to be broadcast in the US next week.
"[The] third episode will deal with the Finn Hudson character being written out of the show," Fox's Kevin Reilly told reporters at a Television Critics Association meeting in August.
The show - now in its fifth series - is known for its upbeat pop covers and cameo appearances by celebrities.