After a high-profile libel case in London, actor Johnny Depp and his ex-wife Amber Heard are headed back to court Monday, this time in the United States, for a blockbuster defamation case revolving about allegations of spousal abuse.

The case pitting the 58-year-old Depp against Heard, 35, will be broadcast live. Both are expected to testify, along with actors James Franco and Paul Bettany -- and billionaire Tesla and SpaceX chief Elon Musk.

The case centres on a column written by Heard and printed in The Washington Post in December 2018 in which she describes herself as a "public figure representing domestic abuse" who was pilloried online after her assault claims.

The column was entitled: "I spoke up against sexual violence -- and faced our culture's wrath. That has to change."

The actress never names Depp, who she met on the set of the 2011 film "The Rum Diary" and was married to from 2015 to 2017 -- but he sued her for defamation for implying he was an abuser, seeking $50 million in damages.

"The op-ed's clear implication that Mr Depp is a domestic abuser is categorically and demonstrably false. Mr Depp never abused Ms Heard," the complaint says.

Depp accuses Heard of seeking to "generate positive publicity for herself" ahead of the release of the film "Aquaman," in which she had a starring role.

Heard countersued, asking for $100 million, saying she suffered "rampant physical violence and abuse" at his hands.

"The frivolous lawsuit Mr Depp has filed against Ms Heard continues that abuse and harassment," her counterclaim says.

Intimate details laid bare

After an ardent legal battle at each phase of the US case, jury selection begins Monday in a county court in Fairfax, outside Washington.

Depp filed his case in Virginia as The Washington Post is printed there. The state also has defamation laws considered to be more favorable to plaintiffs than those in California, where the two actors live.

The trial, presided over by Judge Penney Azcarate, is expected to last several weeks. Opening statements could begin as soon as Tuesday.

Depp and Heard are expected to testify in person, while other witnesses could be heard via video link.

More details about the private lives of the two actors are expected to emerge.

Starting in 2016, Heard sought a restraining order against Depp amid abuse allegations. Their divorce was finalized in 2017.

Depp lost the London case, which he brought against The Sun for branding him a "wife beater." His attempt to appeal was rejected in March last year.

That trial laid bare details of the couple's volatile relationship, including Depp's battle with drugs and alcohol.

Heard testified that she loved the sober Depp -- but that he became a "monster" after days-long binges on powerful prescription and other drugs.

Depp's career has suffered in the wake of that case.

He left his role as Captain Jack Sparrow in the "Pirates of the Caribbean" franchise.

Depp also has said he was asked to step down from the "Fantastic Beasts" film franchise based on the book by Harry Potter author J.K. Rowling. He has been replaced by Mads Mikkelsen.

In a quirk of timing, the next movie in that series opens in US theaters on April 15.