Video: "Red Dog" trailer
Fairfax has reported that the film's producer, Nelson Woss, was devastated to lose his "best mate."
"I'll miss his companionship, his remarkable outgoing, friendly nature and the many long walks that we enjoyed together in Perth and around the country," Woss said.
Koko, a red cloud kelpie, came to live with Woss in retirement after the film was completed, having originally been found by one of the film's dog trainers to star in the film. Koko reportedly learned over 50 commands for the film.
Red Dog, based on the legendary true story of a red dog who united a disparate local community while roaming the Australian outback, was a surprise success for the Australian film industry, earning more than $20 million to become one of the top ten grossing Australian films in history.