Actor Johnny Depp testified on Wednesday at his defamation trial against his ex-wife Amber Heard that it has been "unimaginably brutal" to listen to her "outlandish" accusations of domestic abuse.

"No human being is perfect, certainly not, none of us, but I have never in my life committed sexual battery, physical abuse," the 58-year-old Mr Depp said.

Taking the witness stand as the six-week-long trial in Fairfax, near the US capital, nears an end, Mr Depp was asked by his lawyers what it had been like to listen to Ms Heard's testimony.

"It's insane to hear heinous accusations of violence, sexual violence, that she's attributed to me," the "Pirates of the Caribbean" star said. "All these outlandish, outrageous stories of me committing these things.

"Horrible, ridiculous, humiliating, ludicrous, painful, savage, unimaginably brutal, cruel and all false," he told the jury. "All false."

Johnny Depp said no one "enjoys having to split themselves open and tell the truth" but he needed to address "what I've been carrying on my back, reluctantly, for six years."

The 36-year-old Amber Heard, who was married to Depp from 2015 to 2017, obtained a restraining order against her then-husband in May 2016, citing domestic violence.

Mr Depp, a three-time Oscar nominee, filed a libel suit in London in November 2020 against the British tabloid The Sun for calling him a "wife-beater."

He lost the case and brought suit against Heard over an op-ed she wrote for The Washington Post in December 2018 in which she described herself as a "public figure representing domestic abuse."

The Texas-born Heard did not name Depp in the piece, but he sued her for implying that he was a domestic abuser and is seeking $50 million in damages.

Heard, who had a starring role in "Aquaman, countersued, asking for $100 million and claiming she suffered "rampant physical violence and abuse" at his hands.

 'He never pushed me'

During the high-profile trial which began April 11, Heard testified about multiple instances of alleged physical and sexual abuse by an intoxicated Mr Depp, including being sexually assaulted with a bottle while they were in Australia.

Johnny Depp has claimed Ms Heard was the one who was frequently violent during their relationship and she once severed the tip of one of his fingers by throwing a vodka bottle at him.

Earlier Wednesday, British model Kate Moss, Mr Depp's ex-girlfriend, dismissed reports he once threw her down a flight of stairs.

"He never pushed me, kicked me or threw me down any stairs," said Ms Moss, testifying as a witness on behalf of Mr Depp.

Amber Heard, during her testimony, had mentioned the reports that Johnny Depp was alleged to have once pushed Ms Moss down a flight of stairs.

That reference provided an opening to Johnny Depp's lawyers to call Moss and she testified by video link from England.

The 48-year-old Ms Moss said she had a romantic relationship with Mr Depp from 1994 to 1998.

She was asked about an incident which occurred during a vacation the couple took to a resort in Jamaica.

"There'd been a rainstorm and as I left the room I slid down the stairs and I hurt my back," Kate Moss said.

"And I screamed because I didn't know what had happened to me and I was in pain. He came running back to help me and carried me to my room and got me medical attention."

Kate Moss's testimony lasted just three minutes and Amber Heard's lawyers declined to cross-examine her.

 Damaged careers

After being sued by Mr Depp for defamation, Ms Heard filed a countersuit against him, citing allegedly defamatory remarks made about her by Mr Depp's former attorney, Adam Waldman.

Both sides have claimed damage to their Hollywood careers.

Amber Heard's legal team put an entertainment industry expert on the witness stand who estimated that the actress has suffered $45-$50 million in lost film and TV roles and endorsements.

An industry expert hired by Mr Depp's side testified that the actor has lost millions because of the abuse accusations, including a $22.5-million payday for a sixth installment of "Pirates."

Judge Penney Azcarate has scheduled closing arguments for Friday.