Johnny Depp and Kate Moss (Photo by Ke.Mazur/WireImage)

One of the developments in Johnny Depp’s ongoing defamation lawsuit against ex-wife Amber Heard may end up backfiring on the actress. Heard took the stand in court and recalled past allegedly violent incidences involving her ex-husband, where she claimed the actor struck her.

In her testimony, Heard referenced a rumored violent encounter between Depp and his ex-girlfriend, model Kate Moss.

Heard was describing an argument she had with Depp in 2015, where her sister Whitney Henriquez was “in the line of fire.” Heard claimed that the actor he was allegedly attempting to strike her sister,  who was standing at the top of a staircase.

“I don’t hesitate. I don’t wait. I instantly think of Kate Moss and the stairs, and I swung at him,” Heard said. “In all of my relationship to date with Johnny, I hadn’t landed a blow. And I, for the first time, hit him — like, actually hit him. Square in the face.”

Referencing an old, unverified rumor that Depp pushed Moss down a flight of stairs amid their relationship in the ’90s, Heard may have inadvertently opened an unexpected can of worms.

Lawyer Roland Acevedo, who isn’t involved in the case, told Fox News that it now “opens the door” that Moss could be called in to testify, which could work in Depp’s favor. While the model was not originally listed to testify, Depp reserves the right to call witnesses identified by the defense, in order to confirm or refute Heard’s claims. Moss has never publicly accused Depp of any violent behavior, and the pair are still on good terms.

attends the “Black Mass” Virgin Atlantic Gala screening during the BFI London Film Festival, at Odeon Leicester Square on October 11, 2015 in London, England.

While the former couple’s past heated arguments have been considered public knowledge, Moss told Vanity Fair in 2012 that she cried for “years” over their breakup.

“There’s nobody that’s ever really been able to take care of me. Johnny did for a bit. I believed what he said,” said Moss. “Like if I said, ‘What do I do?,’ he’d tell me. And that’s what I missed when I left. I really lost that gauge of somebody I could trust. Nightmare. Years and years of crying. Oh, the tears!”

When the trial resumes on May 16, actress Ellen Barkin will take the witness stand. Both Depp’s Fear and Loathing in Las Vegas co-star and his ex, Barkin has accused the actor of violence; claims of which Depp has previously denied.

Heard’s sister Whitney and Depp’s sister Debbie are both expected to take the stand as well.