Heartbreaking moment Christian Bale fought back tears as he made comment about Heath Ledger on stage

It isn't often that we see a film where both the protagonist and villain are acted so incredibly well that they are equally popular among the audience.

But that is arguably the case with Christian Bale and Heath Ledger, who became close friends when filming 2008 film The Dark Knight. Ledger tragically passed away from an accidental drug overdose at the age of 28.

Ledger is perhaps best known for his role as the Joker in the Christopher Nolan trilogy, unless you're also a big fan of 10 Things I Hate About You, and he deservedly earned a posthumous Oscar for Best Supporting Actor, which prompted an emotional response from those at the awards.

Heath Ledger (Carlo Allegri/Getty Images)

Bale, who recently outlined the one thing that would make him reprise his role as Batman, was understandably emotional at the MTV Movie Awards back in 2012 after a video was shown of The Dark Knight with scenes that featured the late Ledger.

The now 51-year-old actor said: "Great to remember Heath in that moment, wonderful to see Heath Ledger there."

Following the actor's death, Bale had previously said: "Heath was infectious; his death makes me angry because I know our friendship would have blossomed had he not died."

In a more recent interview, the American Psycho actor maintained his special praise for the Australian actor's 'special' performance in The Dark Knight.

He said: “Heath Ledger, oh my God what a performance and what a pleasure to have got to work with him and to see how much he put himself into the Joker.

“I was watching him going, 'This is absolutely fantastic. Are we in trouble here?'

“When Chris [director Christopher Nolan] and I first sat down we said, ‘You know the problem with Batman is that the villains are always more interesting."

"Batman is actually very close to being a villain himself, so let’s never let him become dull by comparison.

“Unfortunately, I was sitting there going, ‘I feel a little bit dull by comparison’, because Heath is just killing this.

Heath Ledger and Christian Bale in The Dark Knight (Warner Brothers)

“But I’m so proud of that film, I love it.

“The Dark Knight is absolutely extraordinary, and it was such a pleasure to have got to work with Heath.”

Those that knew him will have spoken about his warm personality, but his sensational acting in what remains one of the most popular superhero films of all time, ensures that Heath Ledger will truly never be forgotten.