Amber Heard was "on the precipice of a meteoric rise" before the negative press caused by allegedly defamatory comments made by Johnny Depp's legal team, a court has heard.

Entertainment industry expert Kathryn Arnold, said she believed Ms Heard had lost out on up to $50 million after her claims of abuse by her former partner were labelled a "hoax" by Adam Waldman in 2020.

Mr Depp is suing Ms Heard for $50 million over the article, which his lawyers say falsely implies he physically and sexually abused her while they were together.

Mr Depp has denied all accusations. Ms Heard is counter-suing for $100 million over the comments by Mr Waldman.

Giving testimony in the final week of the six-week defamation case, Ms Arnold said Ms Heard had suffered from a negative publicity campaign on social media, and continued to suffer from lost job opportunities.

Johnny Depp in court

She also said that Mr Depp’s multiple public lawsuits and "erratic behaviour" was contributing to his career decline before the publication of Ms Heard’s article and that the piece had had "zero" effect on his reputation or damages.

"Amber has had a pretty long career for someone who is pretty young still…she had a consistent working actor’s career," she said.

"Her career was following a very nice steady rise and was on the precipice of a meteoric rise with Aquaman and Aquaman 2, prior to the (defamatory) statements."

She added that the resulting backlash online had made it "hard for (brands) to work with Amber on any level because of the negativity brought to their product or service or film" and that the campaign was ongoing.

Aquaman star Jason Momoa

"In the public it’s been very negative, in the industry they like her work but they can’t work with her right now because every time her name is mentioned, the negativity flares up again."

Ms Arnold said that despite questions over Ms Heard not being hired for Aquaman 2, the film’s director James Wan and star Jason Momoa remained "committed" to the actress.

She added that Ms Heard was "comparable" to actors including Mr Momoa, Wonder Woman star Gal Gadot and Zendaya, all of whom have gone on to secure lucrative contracts with brands and other film and television.

Ms Arnold said Ms Heard’s potential losses over a period of five years could potentially be between $45 and 50 million.

Closing arguments in the case are expected to be given on Friday.