Amber Heard has claimed she heard a “rumour” that Johnny Depp pushed Kate Moss down the stairs, during another intense day in the Hollywood star’s blockbuster libel action against The Sun newspaper.

The Aquaman actress told the High Court she rushed to her sister’s aid after she remembered the “information” during an alleged “nasty row” with her ex-husband, when she thought he was going to push her sibling down a flight of stairs.

On her second day in the witness box, Ms Heard, 34, alleged her former co-star James Franco asked her “what the f***?” when he saw her face the day after a separate alleged incident in which she claims Mr Depp was violent towards her.

She has also faced questioning over her relationships Mr Franco and Tesla founder Elon Musk, as well as the infamous “defecation incident”.

Mr Depp, 57, is suing The Sun’s publisher, News Group Newspapers (NGN) and its executive editor Dan Wootton over a 2018 article which labelled him a wife beater.

On Tuesday, Eleanor Laws QC, representing Mr Depp, asked about the “stairs incident” in Los Angeles in March 2015, when Ms Heard has said she believed Mr Depp was going to push her sister, Whitney Henriquez, down the stairs.

The barrister said: “This was a very nasty row between you and Mr Depp and it was you who was the violent one.”

Ms Heard claimed Mr Depp “hit both myself and my sister”, before denying that she spat at the Pirates Of The Caribbean star, or threw a can of Red Bull at him.

Telling the court she “did strike Johnny that day in defence of my sister”, Ms Heard said: “He was about to push her down the stairs and, the moment before that happened, I remembered information I had heard (that) he pushed a former girlfriend – I believe it was Kate Moss – down the stairs.

“I had heard this rumour from two people and it was fresh in my mind.”

She added: “In a flash I reacted in defence of her.”

Ms Heard went on to allege that Mr Depp had punched her “for years” and “for years I had never even hit him”.

She said: “I never so much as landed a blow and I will never forget this incident… it was the first time after all these years (I hit him).”

Ms Laws said Ms Heard had never mentioned the story about Ms Moss before and accused her of “making this up as you go along”.

Earlier, Ms Laws read out text messages between Ms Heard and Mr Musk from May 22 2016, in which Ms Heard tells Mr Musk that she is going to obtain a restraining order against her then husband.

This was the day after an alleged incident at the Eastern Columbia Building in Los Angeles, where Mr Depp and Ms Heard lived, in which the actress claims Mr Depp threw her mobile phone at her, hitting her in the face – which the actor denies.

Questioning Ms Heard, Ms Laws said Mr Musk offers to “arrange 24/7 security for you”, adding: “The offer would stand, even if you never wanted to see me again… anyway, sorry for being an idiot. The radio silence hurts a lot. It only matters because I really like you.”

The barrister then referred to evidence given by Alejandro Romero, a concierge at the Eastern Columbia Building, who said he saw Mr Musk visiting Ms Heard “when Mr Depp was in Australia”.

Ms Heard responded: “He’s wrong. I wasn’t even in communication with Elon until 2016.”

The court was shown CCTV footage of Ms Heard in a lift to her penthouse with Mr Franco, 42, at the Eastern Columbia Building on May 22 2016 at about 11pm.

Asked about the footage, and if the pair, who starred together in The Adderall Diaries in 2015, were “trying to avoid being seen by the camera”, Ms Heard said: “We were talking. He was saying to me ‘oh my god, what happened to you?’

“He saw my face… when I let him in. He saw my face and he said ‘what the f***?’”

Ms Laws asked: “That’s not secretive talking on that camera?”

Ms Heard said: “Yes, it’s discreet.”

Ms Heard also told the court the suggestion she left faeces in the bed she shared with Mr Depp at the Los Angeles apartment is “absolutely disgusting”.

She said it is “unimaginable” that one of her friends left the excrement, which the court has heard was found the day after her 30th birthday party in April 2016, and that she “can’t fathom what adult would ever do such a thing”.

The actress also insisted she had visible injuries in the days following the alleged incident on May 21.

Ms Heard is being questioned over 14 allegations of domestic violence, which NGN relies on in its defence of an April 2018 article that called Mr Depp a “wife beater”.

She has accused Mr Depp of verbal and physical abuse throughout their relationship, including screaming, swearing, punching, slapping, kicking, headbutting and choking her, as well as “extremely controlling and intimidating behaviour”.

Mr Depp, however, says he was “not violent towards Ms Heard – it was she who was violent to him”, and claims his ex-wife was “building a dossier” of false allegations as an “insurance policy for later”.

The actor is suing NGN and Mr Wootton over the publication of an article on April 27 2018 with the headline: “Gone Potty: How can JK Rowling be ‘genuinely happy’ casting wife beater Johnny Depp in the new Fantastic Beasts film?”

His lawyers say the article bore the meaning there was “overwhelming evidence” Mr Depp assaulted Ms Heard on a number of occasions and left her “in fear for her life”.

NGN is defending the article as true, and says Mr Depp was “controlling and verbally and physically abusive towards Ms Heard, particularly when he was under the influence of alcohol and/or drugs”.