Rebel Wilson took out defamation insurance before she went on a social media tirade against a young star, who she accused of lying about sexual harassment by a female producer.

The Pitch Perfect star was all smiles when she arrived at the Federal Court in Sydney on Monday ahead of her defamation showdown against Charlotte MacInnes - the lead actor in musical comedy The Deb, which was directed by Wilson.

MacInnes launched legal proceedings in September after a series of Instagram posts where Wilson accused her of complaining about unwanted sexual advances by producer Amanda Ghost, and then lying about it to get a record contract.

She denies the sexual assault occurred, that she complained about it to Wilson, and that she lied about it in return for a lead role and a record deal.

And in court on Monday, MacInnes' barrister Sue Chrysanthou SC said Wilson's claims were 'a lie' and a 'fabrication by Ms Wilson'.

She said Wilson was angry that she would not get a writing credit in The Deb. She then took out QBE insurance for defamation claims - which can cost millions of dollars '...so she could go ballistic on social media,' Ms Chrysanthou told the court.

Instead of checking in on MacInnes, who Wilson claimed was the victim of sexual harassment, Ms Chrysanthou said Wilson made 'grotesque' claims on her Instagram stories.

'This is how this bully - apparently this saviour of women, the protector of the harassed - responds,' she said.

In her opening statements, Ms Chrysanthou detailed MacInnes and Ghost's trip to Bondi Beach on September 5, 2023, which descended into disaster when Ghost had a medical episode.

She said Ghost had a flare up of a rare condition called cold urticaria, which causes hives or swelling after exposure to cold air or water, so MacInnes took her back to their rented Bondi penthouse and ran a hot bath.

Ms Chrysanthou said MacInnes was also cold and jumped in the bath with Ghost -  their skin didn't touch, they both wore swimming costumes at the time, and they sat with another woman afterwards and drank tea and hot chocolate.

She then referenced texts from Ghost to MacInnes later on the day of the swim, asking what she wanted from a restaurant.

MacInnes replied: 'Chickpea dahl curry please'. 

She then sent a selfie of the pair smiling together on the beach, before Ghost's medical episode. She captioned the photo: 'Beginning of the end'.

Ghost laughed and sent a link about cold urticaria.

Upon receiving the link, MacInnes wrote: 'Oh whoa.' 

Ghost wrote: 'I KNOW I'M A FREAK.' 

Ms Chrysanthou said the texts showed MacInnes had no issue with Ghost and was sending selfies of them together.

She then referenced further texts between Wilson and Ghost, sent on September 7 - two days after the beach swim - that allegedly show MacInnes did not make a sexual assault complaint against Ghost.

'Charlotte says it's all good, she just said it was a bizarre situation so all good there,' Wilson told Ghost via text message.

Ghost replied: 'Of thank f*** for that!! OMG that's hilarious, I nearly died.'

Referring to MacInnes, Wilson said: 'She instantly was like "oh no, zero issues at all" but she said she was happy I called to clarify.'

Ms Chrysanthou then pointed the court to a friendly text Wilson sent to Ghost weeks after the beach trip, saying 'we miss you here in Australia already!!'

In a card to Ghost, Wilson then wrote: 'To dearest Amanda, I cannot express to you how grateful I am for this incredible opportunity to direct this, my dream job.

'I promise you, I will give this my absolute ALL ... Thank you for bringing all your amazing talents to The Deb - you're incredible!' 

Ms Chrysanthou said Wilson did not speak to Ghost as though she was an alleged perpetrator of sexual harassment, but instead allegedly treated MacInnes 'as a liar'.

'Ms Wilson was not a whistleblower seeking to protect a young actress,' she told the court.

'Ms Wilson ran to the alleged perpetrator to say, and she didn't actually say this, but she meant "you're not going to believe what this little liar said about you".'

Ms Chrysanthou said it was a 'very strange attitude' to have against a woman who Wilson claimed was sexually harassed.

Wilson's lawyer Dauid Sibtain SC told the court there was no dispute Ghost and MacInnes bathed together.

He told the court the dispute was whether MacInnes felt uncomfortable bathing with Ghost, who was her boss and working as a senior producer on The Deb at the time.

'They were both wearing their bathing costumes, but Ms MacInnes might have felt some discomfort bathing with her boss,' he said.

'A boss bathing with their employee is not the best practice, even if Ms Ghost was recovering from a medical episode, but it's a position a young employee might not feel comfortable in.'

He alleged MacInnes told Wilson that Ghost asked her to take a bath and a shower with her, but later said she never made the complaint because she 'knew' Ghost 'could make her dreams come true' by helping her land lead roles.

Mr Sibtain said MacInnes hadn't suffered any reputational damage from Wilson's Instagram posts, accusing her of lying about sexual assault. 

'She has continued on with her career at the same rate, and the rate she originally planned,' he told the court.

To emphasise claims that MacInnes' career had not been impacted, he raised one of her recent TikTok posts where she said: 'My biggest flex is I'm doing all the things I said I'd do.'

MacInnes could be seen smiling in disbelief with one of her solicitors, who were both sitting behind Mr Sibtain in court.

'She may have been upset to hear that she's been described as someone who lied to [advance her] career, but it hasn't affected her reputation,' he said.

Mr Sibtain told the court Wilson's claims against MacInnes were published in the form of Instagram stories, which were only available online for 24 hours before disappearing.

He said a small number of people would have seen those stories before they disappeared.

Earlier, Ms Chrysanthou SC told the court that Wilson had failed to provide a series of text messages that she was ordered to produce, and redacted some evidence from the texts.

Ms Chrysanthou said it was not for Wilson to decide whether to conceal evidence by redacting text messages.

'We're very concerned by the approach taken by Ms Wilson and her lawyers in relation to production we find ourselves in a position where Ms Wilson has not produced documents,' Ms Chrysanthou told the court.

'It's very difficult to see how her solicitors had those texts two weeks ago ... and now don't have them, and they don't have the surrounding texts.'

In some instances, Ms Chrysanthou said, Wilson sent expired links from the file-sharing platform, WeTransfer.

Those links were originally meant for 60 Minutes, ahead of an interview Wilson did with Channel Nine journalist Tara Brown.

'She must have the files connected to those links,' Ms Chrysanthou said.

'To provide us with expired links so 60 Minutes can access them is not compliance, and it beggars belief that Wilson does not recall or have a folder on her computer of the documents she provided to 60 Minutes by way of the link. 

'It was in November, it wasn't something that happened two years ago, and the reason we know about the link is because it was referred to in the documents subpoenaed to channel 9.'

Wilson's lawyer Mr Sibtain said they did respond to notices to produce evidence - there was nothing to produce in one category, and some documents had been identified in other categories.

Mr Sibtain told the court some details had been redacted and that Wilson would comply with an order to produce documents by lunchtime on Monday.

According to MacInnes' statement of claim, Wilson's posts accused her of lying about sexual assault and blocking the film's release, and portray her as selfishly prioritising her own career over the hundreds of cast and crew who worked on The Deb. 

She claims Wilson's social media posts damaged her professional reputation and created doubts about her trustworthiness before she played her first lead role in a film. 

MacInnes is seeking aggravated damages for serious harm caused as well as a court order preventing Wilson from repeating the allegedly defamatory claims online.

The matter is one of three legal battles Wilson is embroiled in.

The Deb was a joint production between AI Film and Wilson's company Camp Sugar, featuring Wilson both in the director's chair and on-screen in a starring role.

Three of the film's producers in the US and production company AI Film are seeking damages in the NSW Supreme Court.

That lawsuit claims Wilson made false and derogatory statements about the producers, including the accusations of engaging in inappropriate conduct towards MacInnes.

Wilson called her co-producers' NSW Supreme Court action an act of 'spiteful toxic behaviour' in a lengthy Instagram post last year.

'Apparently I'm being sued in Australia?' she began. 'It makes no sense.

'As the director, producer and co-star who nurtured a project called The Deb for five years from a three-page idea into a gorgeous feature film - I wish nothing more than to have this film released and have been working tirelessly behind the scenes to get this to happen.

'To say otherwise is complete nonsense. I'm so proud of the film!

'In my opinion this is continued bullying and harassment from UK financiers of the project Amanda Ghost, Gregor Cameron and Vince Holden.

'They tried to prevent the film from premiering there (they lost) and now they've tried to stop the film being released because of a baseless US lawsuit and now a further Australian one.'

Wilson said it was 'imperative the movie is released' and added it was 'sad' to see the hard work of 'so many Australians' involved in the film go to waste.

'Contractually, as financiers, they have the power to sell or release/distribute the film,' she wrote. 'They haven't done so.

'It's been a year since the film has been completed and ready to go in cinemas. Instead, in my opinion they have continued this spiteful toxic behaviour.'

Wilson then revealed the first song in The Deb is called F*** My Life and released it for fans to hear 'because if these f***wits aren't going to release the movie I may as well'.

The Supreme Court matter, in which Wilson has filed a cross-claim, was listed for a directions hearing on April 10 - the day after the film's release.

The matter resumes on Tuesday.