Casey Affleck: Joaquin Phoenix Hip-Hip Film Is Not A Hoax

Director Casey Affleck has denied that his new film about actor Joaquin Phoenix’s decision to become a rapper is a hoax.

I’m Still Here premiered at the Venice Film Festival on Tuesday (September 7).

The plot, which follows Phoenix’s career change over a 12-month period, has been met with scepticism from critics.

But Affleck told reporters that it was up the audience to decide what they thought about the film.

"Elliptically, I would say ... I sincerely don't want to influence people's interpretation," he said. "I can tell you there is no hoax. It makes me think of Candid Camera or something."

Phoenix, who is Affleck’s brother-in-law, has also previously insisted that the film was not fictitious.

He attended the film’s premiere but did not speak to the media on Tuesday.

WATCH: I'm Still Here Trailer.