07/16/2013 06:39 EDT | Updated 07/16/2013 10:32 EDT

Cory Monteith Heroin Overdose Death A 'Tragic Accident': Police

Cory Monteith spent the night before he died with three people - one man and two women - Vancouver Police Constable Brian Montague said in a press conference Tuesday.

All three of Monteith's companions have been interviewed by police and cooperated fully, Const. Montague said.

"We are pretty confident we know exactly where they were and what they did last night."

Those details would not be released by police, Const. Montague said, as the police investigation is now concluded.

The press conference came shortly after the BC Coroners Service released its preliminary report into Monteith's cause of death, concluding that the 31-year-old star of "Glee" died due to a "a mixed drug toxicity, involving heroin and alcohol."

When asked if there was evidence of a bad batch of heroin, Const. Montague said that information would not be known until the Coroners Service delivered its final report which would include the levels of drugs and alcohol found in Monteith's body.

There would be no investigation into who supplied Monteith with the heroin as, under Canadian law, there is no provision for any criminal charge related to that.

"There is an inherent risk when you are using illicit drugs," Const. Montague said.

Monteith was found dead in a Vancouver hotel room on July 13th. He had a brief stint in rehab earlier this year.

'Glee' fans have flooded the sidewalk outside the Fairmont Pacific Rim, the hotel where he died, with flowers and other tributes.

“We ask that everyone kindly respect Lea’s privacy during this devastating time,” a representative from actor Lea Michelle, Monteith's girlfriend said over the weekend.

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