Steve Irwin was truly a rare breed of human. Liked by virtually all who ever watched his work, the charismatic Australian dedicated his life to improving the welfare of animals all over the world, as well as educating and entertaining the rest of us while he was doing it.

His tragic death at the age of 44 in 2006 came as a shock despite his often hazardous line of work. Here was a man who wrestled crocodiles, swam with sharks, and handled venomous snakes regularly, and yet the incident that killed him – involving a stingray – was wholly unexpected.

Needless to say, Irwin’s untimely passing prompted an outpour of tributes from his legion of followers around the world. Yet there was some small solace to be taken in the fact that the animal hero died doing what he loved.

Indeed, according to reports, Irwin was so committed to his work that he had a rule in place so that the cameras would never stop rolling, even if he found himself in grave danger.

According to the Daily Mirror, Tommy Donovan, Irwin’s IMDb biographer, once said: “He tells his camera crew to always be filming. If he needs help he will ask for it. Even if he is eaten by a shark or croc, the main thing he wants is for it be filmed. If he died he would be sad if no one got it on tape.”

So it was that the fatal incident that played out near Australia’s Great Barrier Reef on September 4, 2006, was recorded. The story goes that filming for Irwin’s show Ocean’s Deadliest had been postponed due to bad weather, and so the conservationist had decided to film a segment involving stingrays for his daughter Bindi’s show Bindi the Jungle Girl.

Remembering that fateful day, John Stainton, a director and close friend of Irwin’s, told how he, Steve, and camera Justin Lyons were bored at their hotel and so headed out on a small boat to Batt Reef.

Stainton explained: “Suddenly, he expressed interest in encountering some typically harmless stingrays. It should have been an innocuous encounter for a children’s program.”

After chancing upon a 220lb ray resting on the ocean floor, Irwin and Lyons waded into the chest-deep water in the belief that the stingray would swim away from them.

Yet as Steve passed over the ray, it raised its tail to strike, delivering “hundreds of strikes in a few seconds”. With the cameras still rolling, Justin helped Steve back onto the boat and they sped off back towards their main vessel, named Croc One.

“He was struggling to breathe,” Justin recalled. “Even if we had reached an emergency ward immediately, it’s likely we couldn’t have saved him due to the extensive damage to his heart.”

Somewhat morbidly, the entire tragedy, from Irwin getting stung to his last moments alive, were all caught on camera – the footage is said to still exist somewhere today.

John Stainton said of the footage in the days after his friend’s death: “I mean, it should be destroyed. Once it’s released [by the coroner], it should never see the light of day. Never. Never. I’ve seen it, but I don’t want to see it again.”

As per reports, Terri also said that there remains a copy of the film in a police vault.