Officials are looking into the possibility of a drug overdose in the death of "Glee" star Cory Monteith, who was found dead in a Vancouver hotel room over the weekend, investigators told ABC News.

Officials have ruled out foul play in the death.

There will be an autopsy conducted today on Monteith, 31, though determining a cause of death will depend on the results of lab work that will take some time to complete, according to the British Columbia Coroner's Office.

Officials told ABC News they were interviewing Monteith's friends to piece together the last hours of his life, determine why he was in Vancouver and better understand his state of mind at the time of his death.

A drug overdose was an early area of interest based on Monteith's history of drug problems and the lack of foul play indicated by police, officials said, though they emphasized they were open to all possibilities and not drawing any conclusions at this early stage. In fact, on Monday evening, Vancouver police Sgt. Randy Fincham told the AP there's nothing to indicate the death was due to illicit drug use.

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Monteith had been open about his struggle with substance abuse, at one point telling Parade magazine that he took "anything and everything" and was "lucky to be alive." In April, he checked into rehab.

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"If I can, through my experience, shed light on the way out of a difficult situation I know many kids are experiencing, you know, just like I did when I was a teenager, I mean, that's huge," he said in 2011.

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