Margot Robbie thought she was going to get arrested after assaulting Leonardo DiCaprio in Wolf of Wall Street audition

Margot Robbie thought she was going to get 'arrested' after she accidentally assaulted Leonardo DiCaprio in her Wolf of Wall Street audition.

Although Robbie bagged the lead female part in the movie, she unexpectedly found herself in a challenging situation after inadvertently slapping Leo during the audition.

Yes, you heard that right, and the move was entirely unscripted and unexpected.

The Aussie star explained 'what was she thinking' when she delivered a slap right across Leo's face.

"In my head I was like, 'You have literally 30 seconds left in this room and if you don't do something impressive nothing will ever come of it. It's a once-in-a-lifetime chance, just take it'," she told Harper's Bazaar.

"And so I start screaming at him and he's yelling back at me. And he's really scary. I can barely keep up.

"And he ends it saying, 'You should be happy to have a husband like me. Now get over here and kiss me.'

"So I walk up really close to his face and then I'm like, 'Maybe I should kiss him. When else am I ever going to get a chance to kiss Leo DiCaprio, ever?'"

This is where the shocking part comes, and she just took the plunge.

She said: "But another part of my brain clicks and I just go, Whack! I hit him in the face. And then I scream, 'F**k you!' And that's not in the script at all. The room just went dead silent and I froze."

What could have been perceived as a disastrous career move turned out to be the catalyst for Robbie's remarkable ascent to stardom.

Recalling the reaction in the room, Robbie told CBS This Morning: "I was like, 'I think I’m gonna get arrested. Let alone not work in this town,' and then they burst out laughing. They’re like do that again."

Director Martin Scorsese hailed Robbie for her commitment and diligence in the movie, but acknowledged that the crew was equally 'stunned' by the improvisation.

"She clinched her part in The Wolf of Wall Street during our first meeting," he told in Time Magazine's 100 Most Influential People Issue.

"By hauling off and giving Leonardo DiCaprio a thunderclap of a slap on the face, an improvisation that stunned us all."

In an interview on the Screen Time podcast, she said: "I can’t tell you how uncomfortable that was.

"One of my brothers didn’t speak to me for three months afterwards - not because he was mad, he was just, like: ‘I just need a minute before I can consider you my sister again!’"