Johnny Depp has joked that he "killed and ate" his dogs under direct orders of a "sweaty, big-gutted man from Australia" when asked about Pistol and Boo at the Venice Film Festival.

Depp was asked at a press conference for his upcoming film Black Mass whether he was going to take his pooches for a gondola ride in the famed Italian city.

But when his media assistant suggested the question was not appropriate, Depp resorted to joking: "No, I killed my dogs and ate them, under direct orders of some kind of, I don't know, sweaty, big-gutted man from Australia."

Johnny Depp and his wife Amber Heard attend the red carpet event in Venice. ( Reuters: Stefano Rellandini )

The joke was a reference to a dispute between the actor and Agriculture Minister Barnaby Joyce earlier this year, when the Hollywood star and wife Amber Heard brought Pistol and Boo to the Gold Coast while Depp filmed the latest Pirates Of The Caribbean movie.

Mr Joyce said the dogs had been illegally imported without meeting Australia's import conditions and issued an ultimatum that Depp either fly the dogs out of Australia or they would be put down.

"There is a process if you want to bring animals: you get the permits, they go into quarantine and then you can have them," Mr Joyce said at the time.

"But if we start letting movie stars — even though they've been the sexiest man alive twice — to come into our nation [and break the laws], then why don't we just break the laws for everybody?

"It's time that Pistol and Boo buggered off back to the United States."

The Commonwealth Director of Public Prosecutions has issued a summons against Heard who has been charged over a biosecurity breach.

She is due in a Queensland court this month.