Kate Moss says Johnny Depp never threw her down any stairs

British model Kate Moss has dismissed reports that her former boyfriend Johnny Depp once threw her down a flight of stairs, saying it never happened.

"He never pushed me, kicked me, or threw me down any stairs," said Moss, who was testifying as a witness at Depp's defamation trial against his former wife Amber Heard.

The 58-year-old Depp filed 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."

Heard, 36, did not name the Pirates of the Caribbean star in the op-ed, but he sued her for implying he was a domestic abuser and is seeking $50 million in damages.

The Texas-born Heard countersued, asking for $100 million and claiming she suffered "rampant physical violence and abuse" at his hands.

Heard, during her testimony earlier this month, mentioned a reported incident in which Depp was alleged to have pushed his former girlfriend Moss down a flight of stairs.

That reference provided an opening to Depp's lawyers to call Moss as a witness to address the allegation and she testified by video link from Gloucestershire, England.

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

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

"We were leaving the room and Johnny left the room before I did," Moss said. "And there'd been a rainstorm and as I left the room I slid down the stairs and I hurt my back."

"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."

Heard's lawyers declined to cross-examine Moss. (AFP)