Film star Johnny Depp's dogs, Boo and Pistol, flew back to the United States from Australia on Friday (15 May), a day after the Australian agriculture minister warned him to send the pair home to be quarantined or face having them put down.

Depp, who is in Australia to film the fifth instalment of his blockbuster pirate movie series, Pirates of the Caribbean: Dead Men Tell No Tales, also faces a formal interview with government officers into how the Yorkshire terriers were allegedly smuggled in, a spokesman for minister Barnaby Joyce said.

The incident highlights tough animal security laws in Australia, which has had no reported cases of rabies among dogs.

Last month, Depp flew in the dogs on his private jet, without declaring them to customs but government officials followed a tip-off after they were seen on the way to a grooming salon.

An online petition calling on Joyce to spare the dogs now has 17,500 signatures and has sparked a debate on Twitter.