Quentin Tarantino warned Brad Pitt he'd be 'dead in this business' after film faux pas

Quentin Tarantino told Brad Pitt he'd be "dead in this business" after Once Upon A Time In Hollywood faux pas.

The iconic filmmaker, 63, looked "insanely grave" after the 62-year-old actor overstepped his boundaries on the set of the 2019 epic, and he warned him never to make the same mistake again.

Bruce Dern, who played blind ranch owner George Spahn in the movie, has recalled a moment he delivered one of his infamous improvised 'Dernsie' moments during filming.

The 89-year-old big screen veteran told PEOPLE magazine: "When Brad Pitt wakes me up in Once Upon a Time… in Hollywood, I’m in the bed and I get up and I’m a little groggy and stuff and I just say, 'I’m not really sure what’s going on'.

"I’m looking at him. [Pitt] cut the camera. He cut the camera. The look on Quentin’s face — I mean, he was insanely grave — and he said, 'Brad, what did you just do?'

"He said, 'Well, I cut the camera.' He said, 'Never again in your life will you ever cut a camera or you’ll be dead in this business. That’s my domain. Don’t stop behaviour.' "

The pair redid the scene, but Pitt - who starred stuntman Cliff Booth alongside Leonardo DiCaprio's Rick Dalton in the film - wasn't impressed by the changes to the script.

Dern revealed: “So then we went on and did the scene and all Brad did was say to him, 'Well, that wasn’t in the script what he said.' "

The crew kept filming, and Dern ended up improvising another line.

He said in the scene: “I don’t know who you are, but you touched me today. You came to visit me, now I gotta go back to sleep.”

Pitt is set to reprise the role of Cliff an as-yet-untitled Netflix spinoff Upon A Time In Hollywood, which will get a two-week Imax run from November 25.

Tarantino has written the script, but the movie will be helmed by David Fincher, meaning it won't count as the former's highly anticipated 10th and final directorial project.

Speaking on The Church of Tarantino podcast, the Pulp Fiction filmmaker explained: “I love this script, but I’m still walking down the same ground I’ve already walked.

“It just kind of unenthused me. This last movie, I’ve got to not know what I’m doing again. I’ve got to be in uncharted territory.”

Even so, Tarantino insisted Fincher was a perfect pick to direct the Cliff Booth spinoff.

He added: “I think me and David Fincher are the two best directors.

"So the idea that David Fincher actually wants to adapt my work, to me, shows a level of seriousness towards my work that I think needs to be taken into account."