Steve Irwin knew he was dying after a massive stingray stabbed him in the chest hundreds of times, the only witness to the 2006 attack said in his first detailed public account of the conservationist's death.

"We're saying to him things like, 'Think of your kids, Steve - hang on, hang on, hang on'," Justin Lyons said.

Irwin's long-time cameraman told Australia's Studio 10 morning show: "He just sort of calmly looked up at me and said, 'I'm dying'. And that was the last thing he said."

In the nearly eight years since Australia's famed Crocodile Hunter died, Mr Lyons has said little publicly about how the fatal encounter with the stingray unfolded. Now, he said, he wanted to clarify how Irwin died, including dismissing reports that his friend pulled the stingray's barb out of his own chest.

"The stories at the time of Steve's death - none of them were accurate because no one else was there," Mr Lyons said in an interview. "And that always bothered me."

He is also speaking out now because he has just finished producing a documentary, E-Motion, which examines the impact that repressing negative emotions can have on the body.

"I thought that it was a great way to illustrate my experience with Steve; holding on to these traumatic events can be very, very bad," he said. "I'm happy that I've finally spoken about it publicly. It has been, I guess, a weight on my shoulders."

Mr Lyons still vividly remembers the day he lost his friend, who rose to fame on his TV series The Crocodile Hunter. The two were shooting a wildlife documentary in the Great Barrier Reef when they spotted an 8ft-wide stingray.

They had been filming the creature for several minutes in chest-deep water and decided to try to get one final shot of the stingray swimming away. Suddenly, the animal began wildly stabbing Irwin with the barb on its tail - hundreds of strikes within seconds, Mr Lyons said. The barb went through his chest "like a hot knife through butter," piercing his heart.

"It probably thought that Steve's shadow was a tiger shark, which feeds on them very regularly," he told Studio 10. "I didn't even know it had caused any damage. It wasn't until I panned the camera back that Steve was standing in a huge pool of blood that I realised something had gone wrong."

Mr Lyons and his crew threw Irwin into their boat and put pressure on the gash over his heart, which was seeping blood, and Mr Lyons performed CPR, but the damage was too severe. The 44-year-old died later that day, leaving behind his wife Terri and two young children.

The fact that Irwin - who was notorious for his extremely close encounters with crocodiles, sharks and other potentially lethal animals - died after a run-in with a normally docile creature shocked the public, but Mr Lyons said he always had a sense his friend would meet an unusual end.

"It was never going to be a croc or a shark," he said. "He was so good with animals."