Quentin Tarantino's Once Upon A Time In Hollywood premiered at the Cannes Film Festival this week. And while many are talking about the all-star cast, which includes Leonardo DiCaprio, Margot Robbie and Brad Pitt, many are also taking Tarantino to task after he snapped at a female reporter the at film's photo.

During a media session at the annual film festival, the reporter asked Tarantino why Robbie, with her immense resume of films, didn't have more dialogue in her role as '60s icon Sharon Tate.

"Quentin, you have put Margot Robbie, a very talented actror, in your film. She was with Leonardo in The Wolf Of Wall Street, I, Tonya...this is a person with a great deal of acting talent and yet you haven't really given her many lines in the movie. I guess that was a deliberate choice on your part and I just wanted to know why that was and why we don't hear her speaking very much," the reporter said.

Tarantino tersely responded, "Well, I just reject your hypothesis", with no further explanation.

In stark contrast, Robbie, who was also asked to comment, calmly responded to the reporter at length, explaining that the development of Tate's character didn't require dialogue.

"I think the moments I was on screen gave a moment to honour Sharon. I think the tragedy was the loss of innocence. To show the wonderful sides of her could be done without speaking," Robbie said.

"I did feel like I got a lot of time to explore the character without dialogue, which is an interesting thing. Rarely do I get an opportunity to spend so much time on my own as a character."

Once Upon A Time In Hollywood is a semi-true crime retelling of the Manson Family Murders, and many critics are describing it as the Kill Bill director's greatest film since Pulp Fiction.

The film premieres in Australia on August 15.