Hollywood star Rebel Wilson says claims she bullied women on her film are "absolute nonsense" as she gave evidence for the first time in a high-profile defamation case against her in Sydney.

The Bridesmaids actress is being sued by a young Australian actress Charlotte MacInnes - who stars in Wilson's directorial debut, The Deb - over a series of Instagram posts in 2024 and 2025.

MacInnes says Wilson ruined her reputation by calling her a liar for complaining about sexual harassment by producer Amanda Ghost but later recanting it to further her career. MacInnes says she never made such a complaint.

On Tuesday, prosecutors asked if Wilson saw herself as a "champion of women" to which she said yes.

Her response was delivered to a packed courtroom filled with a mix of journalists, supporters and several witnesses - Ghost among them.

Sue Chrysanthou SC, acting for MacInnes, was forceful on her cross-examination of Wilson with a tense atmosphere filling the room as she opened her questioning.

She began by asking the actress about her criticism of women working on The Deb, accusing her of mistreating MacInnes, Ghost and a female writer, despite saying she is a champion of women.

"That's absolute nonsense," Wilson told the court.

Wilson also denied that making public, negative statements about women on social media could be defined as mistreatment because they are "truthful".

Under questioning, Wilson repeatedly said she could not remember various details of the case and also denied any involvement in websites that spread rumours about Ghost and MacInnes.

She also could not recall the backlash in 2018 when she made comments about being the "first ever plus-sized girl" to star in a romantic comedy, after Chrysanthou raised it.

In court, prosecutors labelled Wilson a liar, a claim that the actress firmly denied, saying the accusation was "outrageous".

The incident at the heart of the defamation case dates back to September 2023, when MacInnes and Ghost, a producer on The Deb, went to Bondi Beach for a late afternoon swim.

Ghost had an allergic reaction to the cold water, known as cold urticaria, breaking out in red welts and shaking uncontrollably, the court heard last week.

The pair rushed back to Ghost's beachside apartment where MacInnes ran a hot bath for Ghost, who had already gotten into a shower to warm up.

MacInnes climbed into the bath first in a bid to warm up too, and Ghost later joined her. Both were wearing their swimsuits.

At one point, Ghost's assistant brought hot drinks for the pair and they all chatted briefly in the bathroom.

The court heard that Wilson, who is relying on the truth defence, spoke to MacInnes about the incident and while both sides acknowledge the conversation happened, the content of the chat remains in dispute.

Wilson says MacInnes told her the bath incident had made her feel "uncomfortable" but MacInnes denies she said this, and only described the situation as "weird" or "strange and bizarre".

In her evidence last week, MacInnes told the court that Wilson had "mischaracterised and exploited" an "innocent incident" and her relationship with Wilson deteriorated during filming of The Deb in the months after the bath incident.

The court was also shown text messages that Wilson sent Ghost, saying MacInnes had "zero issues" with the incident.

"Charlotte says all good," Wilson wrote in a message to Ghost, relaying her conversation after speaking with MacInnes.

"She just meant 'it was a bizarre situation' not that she personally felt uncomfortable."

Last week in court, Wilson's lawyers claimed that MacInnes's career had not been hurt by the social media posts, and in fact, her career had flourished with a record deal with major label Atlantic and a role in a US theatre show produced by Ghost.

MacInnes is suing for aggravated damages over Wilson's posts and to stop Wilson from repeating those claims online.

The court also earlier heard allegations by the prosecution that Wilson had ordered a US public relations firm to create websites to paint Ghost as an "Indian Ghislaine Maxwell".

Maxwell is currently serving a 20-year sentence for grooming and trafficking underage girls for Jeffrey Epstein.

Another issue raised by prosecutors in court last week involved the leaking of a nude photo of MacInnes after her social media accounts were hacked.

Wilson is expected to continue giving evidence on Wednesday.