Cory Monteith's father said they are still grappling with 'Glee' star's death due to an accidental overdose of heroin and alcohol.
Joe told Entertainment Tonight Canada that it was Monteith's mother who first discovered that her son had a drug problem.
"I guess he was involved a little more in drugs than anybody knew at the time. His mother who was there with him all the time, she started picking up on it, you know stuff was missing, money here, stuff like that."
Joe, who was estranged from his famous son until recently, said they could not believe the news when they first heard it.
"When they did break the news to my wife, she almost fell over, in fact, I had to grab her. And I had to ask them again what was that you said? It really didn't sink in. It still really hasn't," said Joe, who divorced Cory's mother, Ann McGregor, when Cory was 7.
Monteith's body was cremated in Vancouver following a private viewing with his mother, brother Shaun, and girlfriend Lea Michele.
Joe did not attend the funeral and said he was "totally devastated" that he didn't get a chance to say goodbye.
"I always loved both my sons and am going to miss Cory very, very much. I'm saddened at the fact that I couldn't have been there to see my son before he was cremated."
The actor had recently completed a stay in rehab to overcome his addiction, but he had relapsed. He was found dead in his room at the Fairmount Pacific Rim hotel in Vancouver on July 13.
