Eighteen-year-old model Taylah Roberts attacked rival contestant Ashley Pogmore, 18, during the filming of an episode of the show at Broken Hill in New South Wales.
In the upcoming episode which airs tomorrow night, the contestants throw paint on each other after participating in an art class.
But Roberts lashes out when she realises there is paint on her shirt, attacking the instigator of the paint fight, Pogmore, by placing her hands around her neck.
"It was getting really tight and I could just feel my neck hurting and I could feel my face going red and that's when I've kind of wrapped my legs around her and then we've fallen into the bushes and she's landed straight on top of me on my chest," Pogmore told A Current Affair.
"We were laughing and then it got to that point where I don't think she really realised her own strength."
Roberts apologised for her actions, stressing violence was never the right reaction.
"It's just one of those things that just happened so quickly and once I'd done it, I knew that it was the wrong thing to do," the model hopeful said.
And Pogmore was quick to defend her fellow contestant.
"Obviously violence isn't right and I'm not sitting here defending what she's done, but I'm defending who she is as a person," Pogmore said.
Australia's Next Top Model judge, Charlotte Dawson, said the incident was kept within the girls and producers.
"It was like a playground situation where maybe a stronger character picks on a more vulnerable character and things get out of control," Dawson said.
“I mean it happens too much in the playground so we can't tolerate it on our show…It’s very polarising. It went from fun to serious.”
Dawson said she was concerned about the social media backlash that the girls would face as a result of the incident.
Roberts said it was the pressure of the situation that caused her to lose her cool.
"There's so many viewers of the show and a lot of the top agencies do see the show as well so I worry they'll see it and think that I'm unprofessional or that I can't control anger," she said.
Australia's Next Top Model airs on Fox 8 at 7:30pm tomorrow night.