Batman: The Killing Joke
The Joker on the cover of Alan Moore's famous graphic novel The Killing Joke.DC Comics

Warner Bros reportedly wants Leonardo DiCaprio to play Batman villain in The Joker in its planned origin movie about the Clown Prince of Crime. Martin Scorsese's involvement in the project is believed to how the studio hopes to woo the Oscar-winner.

Last week (22 August) plans were revealed for an origin tale co-written and possibly directed by The Hangover's Todd Phillips, alongside 8 Mile scribe Scott Silver and with Scorsese on board as a producer.

The Hollywood Reporter believes that Warner Bros wants DiCaprio, or another A-lister, to play the iconic character "as a gritty crime boss in a Scorsese-esque Gotham underworld".

As initially reported, the film is intended to stand separately from the shared universe of DC superhero properties which has included Batman v Superman: Dawn of Justice and Wonder Woman.

The story cites an insider claiming that Jared Leto - who played the Joker in last year's critically-panned Suicide Squad - was "caught off guard" by the development, voicing his displeasure with his agents.

Leto is on board to portray the character a second time in the Suicide Squad sequel, and potentially a third time in another project.

Wanting Leonardo DiCaprio to play The Joker is one thing, actually getting the Wolf of Wall Street and Revenant star to sign up is something else entirely and is certainly very unlikely to ever happen.

DiCaprio has steered well clear of traditional blockbusters in his post-Titanic career, only coming close with 2010's Inception. For him to enter the world of superhero movies would be a shocking move for an actor that takes himself so seriously.

The Scorsese connection is certainly strong however, given how frequently the pair have teamed up on films including Shutter Island, Gangs of New York and The Departed. In July it was reported that they may team up once more for Scorsese's adaptation of Killers of the Flower Moon.

Warner Bros' Joker origin story has been met with criticism due to the very nature of what such a film would mean for a character whose mysterious origins are a large part of his appeal. In 2008's The Dark Knight, Heath Ledger's Joker hinted at multiple origin tales, clearly lying about most, if not all of them. This is typical of the character, and lends to his mystique.

Which isn't to say The Joker's origin can't be told at all. Alan Moore's The Killing Joke - considered one of the greatest graphic novels ever produced - told his story with enormous success.