Morgan Freeman insists Heath Ledger's death had nothing to with him playing The Joker in The Dark Knight.

The 28-year-old actor died in January 2008 from an accidental drug overdose and while some people believe he was struggling to cope with the intensity of playing the maniacal character, co-star Morgan isn't convinced the role played any part in his untimely passing.

"Well, it's a downer when anything happens to an actor in mid-production. In fact, he didn't die during production, his part was wrapped up, but the movie itself wasn't out yet. People connected the character to his death because the character was so ... evil. People imagine that the role leaks into the man or something. And I don't think that was the case at all," Morgan said, speaking of Heath's tragic death.

Morgan - who has reprised his role as Lucius in new Batman film The Dark Knight Rises - also revealed he has no intention of retiring from acting even though he's 75: "What keeps anyone going? I have work. I have things to do. I prefer working to idleness. And I like my job. I'm lucky, I'm not working because I have to; I'm working because I love to."