Cory Monteith Cory Monteith

Sunday marks the one-year anniversary of Cory Monteith's tragic death and the Glee star's father, Joe Monteith, continues to mourn him deeply.

"I still miss him very much and I still have the empty feeling," Joe told ET Canada.

See more celebrities we've lost this year

Monteith was found dead from an overdose of heroin and alcohol in a Vancouver hotel room last July. Joe had an estranged relationship with his son for the majority of his life, but the two had begun to tentatively reconnect in Monteith's final years. However, Monteith's mother, whom Joe divorced in 1989, didn't inform him of the funeral plans.

"I didn't get to go to his viewing, which, it would have meant a lot," Joe said.However, Monteith's mother has since reached out, offering to send Joe some of the late actor's possessions.

Cory Monteith's 10 most memorable Glee performances

Now, Joe tries to focus on the positive memories of his son, and says he misses his son's charismatic presence most. "Cory was a likeable young man and if he was in the room, you'd be smiling," he said. "He enjoyed life. That's why I was so shocked about the outcome of everything."