Johnny Depp throws gross accusation at ex-wife Amber Heard

The marriage between Amber Heard and Johnny Depp imploded after a violent argument about poo, a friend claims. Photo / Getty Images

Johnny Depp has accused former wife Amber Heard of deliberately soiling their marital bed in revenge for turning up two hours late to her 30th birthday bash.

The troubled actor claims the incident sparked the violent argument that led to the breakdown of their marriage.

Depp had stormed out of the couple's Los Angeles penthouse after discovering the pile of poo between the sheets after Heard's party in April 2016, a friend of the Pirates of the Caribbean star told The Mirror.

Heard blamed the deposit on her dog Boo, who has bowel problems, but a housekeeper who had to clean up the mess the following day suggested the droppings were too large to have come from the little pooch.

Depp, 55, believes there is "strong, photographic evidence that connected Amber to the faeces" and it was left as a "prank", the friend said.

But a representative for the actress denied any malicious intent, insisting it was an unfortunate accident.

"Boo has some serious bowel control issues. There was never a joke, it wasn't something done to be disrespectful," the rep told the Mirror.

"It was an innocent thing, it's what pets will do. We don't have anything else to say. Ms Heard is moving on and we do not want to engage in this nonsense."

In May 2016, a month later, the couple had another argument about the poo which turned violent and culminated in Depp allegedly hurling Heard's mobile phone, hitting her in the face.

Johnny Depp claims ex-wife Amber Heard deliberately soiled their marital bed in revenge for his lateness but she says her beloved pooch Boo was to blame. Photo / Instagram

The actress later posted photographs of her bruised face to Instagram and applied for a restraining order against Depp.

Heard hinted at the bizarre stoush in court documents, claiming Depp made "paranoid and

irrational accusations about some delusional idea".

"He began obsessing about something untrue and his demeanour changed dramatically. He became angry," she said.

Heard withdrew the application for a restraining order following their divorce settlement, in which he agreed to pay her US$7million, which she donated to charity.

Depp denies he was ever violent to Heard.

It's not the first time Boo and his stablemate Pistol have made headlines.

In 2015, Australian former deputy prime minister Barnaby Joyce threatened to put the Yorkshire terriers down after Heard and Depp illegally smuggled them into the country during the filming of the fifth Pirates of the Caribbean movie on the Gold Coast.

The couple later claimed they had no idea they were breaking Australia's quarantine laws and filmed a much-ridiculed apology that was linked to a "hostage video".