Christian Bale is angry at the tragic death of actor Heath Ledger - because he's convinced the pair would be firm friends if he was still alive.

Bale, who stars alongside Ledger in new Batman movie The Dark Knight, had developed a bond with the Brokeback Mountain star during filming.

And he's sad he never got the chance to explore their friendship further.

Bale says, "He was a fantastic guy, we had a lot of fun on set. Yes, he immersed himself into the film completely, but, at the same time, he was so easy-going.

"Heath was infectious; his death makes me angry because I know our friendship would have blossomed had he not died."

Bale also referred to reports Ledger had put too much of himself into his role as the Joker.

He adds, "I keep catching myself talking about him in the present tense, which is very upsetting.

"I was obviously with him at that time, but I can only speak for myself. Yes, sometimes I look back and think, 'OK, maybe I went a little bit too far, committed a little bit too much of myself'. But I don't regret doing it."

Ledger died from an accidental overdose of prescription drugs in New York last January (08).