Cory Monteith, who was found dead late Saturday night in Vancouver's Fairmont Pacific Rim hotel, battled with drug addiction and alcoholism while in Vancouver, but tried to stay clean during his stay in Los Angeles, TMZ reported.

According to the report, Monteith’s girlfriend, Lea Michele, and his Glee cast members kept him away from drugs and alcohol while shooting the series. But, once back in Vancouver, Monteith’s lifestyle spiraled out of control, aided by a group of friends who fuelled his addiction, TMZ reported.  

Just days before his sudden death, Monteith was spotted drinking at a local restaurant in Vancouver, despite his recent stint in rehab to kick the addiction. Although he did not appear to be inebriated, a customer at the restaurant told TMZ that he “knocked back 3 cold ones over the course of a few hours.”

According to reports, an autopsy of Monteith’s body was completed on Monday afternoon, and officials have ordered a toxicology report to determine what caused the death. The decision to do a toxicology report was made due to his history with substance abuse, Billboard reported.

Monteith had always been open about his struggles with addiction, which he once said, started at the age of 13. In an earlier interview with Parade magazine, Monteith said that his decision to kick the habit stemmed from an incident where he stole money to aid his addiction.

"I knew I was going to get caught, but I was so desperate I didn't care. It was a cry for help. I was confronted and I said, 'Yeah, it was me.' It was the first honorable, truthful thing that had come out of my mouth in years," he told Parade at the time.