The stars worked together on 2002's The Four Feathers and Bentley admits he greatly misses Ledger, seven years after he suffered an accidental drug overdose.

He says, "He was like a brother to me... We had become very, very close. We had good times and bad times... (his death is) the biggest loss of my life."

Bentley also opened up about his own struggles with addiction, revealing he once considered quitting acting to support his habit.

He states, "The drugs got harder and I got deeper in it, and I started considering things like selling (drugs) and DJing for a living instead of acting."

The actor managed to turn his life around after seeking help in rehab in 2009, and he has been sober ever since.

He adds, "Some people have one bottom, I had 10 or 12 bottoms: a friend who passed away; I had no money; I lost contact with my family.

"I finally met somebody who I loved and that kind of turned around. And then I met somebody who was sober and I wanted what he had. And then I worked really hard. I still work really hard."