Isla Fisher makes first appearance since Rebel Wilson accused husband Sacha Baron Cohen of sexual harassment

Isla Fisher has made her first public appearance since Rebel Wilson made explosive allegations against her husband Sacha Baron Cohen, accusing him of sexual harassment on a film set.

The Australian actor, 48, stepped out for a night in London with friends and fellow Australian talents, actress Naomi Watts and film producer Bruna Papandrea, and British actress Michelle Dockery.

Fisher shared a selfie the group took at the Harold Pinter Theatre, where they watched a production of the play The Hills of California, to her Instagram captioned: “Girls night at the theatre”.

It is the first post and public outing since her husband, comedian Sacha Baron Cohen, was accused of sexual harassment by Rebel Wilson.

Wilson, 44, said she adopted a “no a...holes policy” on set after working with Cohen in the 2016 film The Brothers Grimsby, during which she said the comedian asked her to film nude scenes and made her feel “scared” on set.

People magazine shared an excerpt of the book in which Wilson recalled an incident in which Cohen allegedly pulled down his pants and told her to “stick [her] finger up [his] ass” as part of an “extra scene”.

“I was now scared. I wanted to get out of there, so I finally compromised: I slapped him on the ass and improvised a few lines as the character,” she wrote.

Cohen’s spokesperson denied the allegations and the comedian is believed to have engaged lawyers amid the mounting speculation about the memoir’s contents.

“While we appreciate the importance of speaking out, these demonstrably false claims are directly contradicted by extensive detailed evidence,” Cohen’s spokesperson previously said in a statement.

“Including contemporaneous documents, film footage, and eyewitness accounts from those present before, during and after the production of The Brothers Grimsby.”

The DailyMail.com obtained clips from The Brothers Grimsby that were left out of the movie that appear to depict Wilson and Cohen’s characters — Dawn Grobham and Norman Butcher — using a mobile phone to film themselves getting intimate.

Sources said any nudity or sex scenes had to be discussed with the actors before they were shot, and that Wilson agreed to do the scene.

Wilson said releasing the clips was an “a...hole move” by Cohen that left out “everything that preceded it including my horrified refusal to stick my finger up SBC’s butt.”

She said the “edited video” shows what she “had to do in order to get out of the room”.

Despite fans questioning Fisher on the allegations against her husband, the actress — who also starred in The Brothers Grimsby as Jodie Figgs — has refused to comment on the matter publicly.

Rebel Rising was set for release on April 3 but has reportedly been cancelled amid the mounting speculation of legal threats.