It's a villainous role previously played by some of Hollywood's finest - including Jack Nicholson and Heath Ledger.

And Joaquin Phoenix was spotted for the first time as The Joker, as filming started for the forthcoming movie of the same name.

The 43-year-old actor looked like he'd lost weight for the titular role, as he shot a scene in NYC which saw him encounter a clown.

On set: Joaquin Phoenix was spotted for the first time as The Joker, as filming started for the forthcoming movie of the same name

Joaquin - who has been dating Rooney Mara since 2016 - looked to be perfecting the Joker's maniacal smile, as he walked the backstreets of Harlem, which were posing as Gotham City in the 1980s.

With trash piled up in the background, Joaquin is seen holding a cigarette and brown paper carrier bag.

He was not yet wearing the Joker's distinctive make-up.

His brown hair is tousled and worn long and loose, as he approached a clown, and was seen pulling off his red nose.

Noses off: The 43-year-old actor looked like he'd lost weight for the titular role, as he shot a scene in NYC which saw him encounter a clown

The origin story - which is due for release on October 4, 2019 - sees Joaquin in the titular role despite Jared Leto most recently playing The Joker in Suicide Squad.

The movie has Martin Scorsese as one of its producers, and THR reports that Robert De Niro will be in the movie as 'a talk show host who is somehow instrumental in the Joker’s origin.'

Marc Maron is also apparently appearing as 'an agent on Robert De Niro’s talk show who plays a part in booking Phoenix’s character, and eventually causing him to go mad and become the Clown Prince of Crime,' according to Variety.

Circus act: He approached a clown, and was seen pulling off his red nose

Crazed: The exchange was the first time Joaquin has been seen in character as filming started

Not laughing now: Joaquin walks away whilst puffing on a cigarette

Sinister: Joaquin looked to be perfecting the Joker's maniacal laugh, as he walked the backstreets of Harlem, which were posing as Gotham City in the 1980s

Stepping out: With trash piled up in the background, Joaquin is seen holding a brown paper carrier bag

Deadpool 2 actress Zazie Beetz will play 'a single mother who catches the interest of the man who will become the clown prince of crime,' also reports THR.

Frances Conroy will play the Joker's mother, Penny, while Frances Conroy will play the Joker's mother, Penny.

The origins story will reportedly be loosely based on the origin story written by Alan Moore 30 years ago in The Killing Joke.

Holy smokes: Joaquin was seen puffing away on a cigarette as he filmed the scenes

In that version the Joker quits his job as a Lab assistant and becoming a stand-up comedian to support his pregnant wife.

Unsuccessful, he agrees to help mobsters with a robbery and dons the Red Hood, however, the heist goes awry.

The comedian leaps into a chemical vat to escape Batman, surfacing disfigured and this, combined with the earlier accidental death of his wife and unborn child, drives the comedian insane and he becomes the Joker.

On the move: Joaquin looked immersed in his character as he made his way around the set

Joaquin is the younger brother of late actor River Phoenix, and was known as Leaf in his early career.

When chatting recently with Collider, Phoenix admitted that playing The Joker 'scares the f***ing s**t' out of him.

'Writers and directors and fans have their expectations, and they’ve imagined things in their head, and they’ve imagined different actors, and suddenly you take it on and so there’s this moment of anxiety of "Did I live up to their expectations?" he said.

He has three Best Actor Oscar nominations - for Gladiator, Walk The Line and The Master.

He will next be seen on the big screen on September 21 in western dark comedy The Sisters Brothers alongside John C. Reilly and Jake Gyllenhaal.