The Deb actor alleges Rebel Wilson made up sexual assault claims

The Australian actor at the centre of Rebel Wilson's defamation case has claimed her accusations of sexual assault are false.

The complex legal spat between Wilson, who directed The Deb, and the film's three producers - Amanda Ghost, her husband Gregor Cameron, and Vince Holden - just got even more confusing.

Charlotte MacInnes, who stars in the comedy that premiered in September, claims Wilson repeatedly said Ghost had sexually harassed and abused MacInnes, despite her telling Wilson that no such incidents had taken place.

"Nothing that I told Wilson could reasonably have conveyed that I was reporting any misconduct, because there was no misconduct," MacInnes alleged in the lawsuit filed in a Los Angeles court.

"I also understand there were claims that I was subjected to 'depraved sexual demands'. These statements are completely false and absurd. I have no idea what could cause Wilson and her lawyer to make up such lies about me."

The alleged sexual misconduct is one of several accusations made by Wilson, which led the film's producers to sue the Australian actress for defamation.

In response, Wilson is countersuing in an effort to have the defamation claims against her dismissed.

With a dispute over writing credits also on the table, the legal battle could result in millions in legal fees for both sides.