The sad story behind that 'man-punching-a-kangaroo' video

It's basically the most Aussie video you'll ever see - a man squaring off with a massive kangaroo which he then punches in the face.

The footage has gone viral after the huge animal put his hunting dog, Max, in a vicious headlock.

But while the world has been caught up in the #Straya of the toe-to-toe, there's much more to the story than meets the eye.

"This hunting trip was put together for a sick young man called Kailem who passed away from cancer last week," said Mathew Amor, who organised the hunting trip in June when the incident occurred.

Mr Amor told news.com.au he decided to organise a small group of friends, including Kailem, to go on the boar hunting trip at his property in Euabalong, New South Wales, after hearing about Kailem's deteriorating condition.

"Basically Kailem wanted to catch a boar," Mr Amor said.

"And so a few of us got together to take him out, and another mate filmed more than an hour of video to put together as a DVD for Kailem and his family of the trip."

Mr Amor would only share the nickname of his famous friend who punched the kangaroo - "Goo" - and said it was really out of character for the "placid bloke".

"My mate has a good government job, so he's gone pretty quiet on this," Mr Amor laughed.

"We were driving along, the dogs are loose. They are trained to smell pig's blood, and picked up a scent.

"The dogs went past 20 kangaroos, which they are trained not to touch.

"Anyway, this big buck got a hold of my friend's dog. It just grabbed him."

"He [hunter] went in to save the dog but when the roo turned towards him, he stood his ground as well until all the dogs were safe," Mr Amor said.

"The dog Max was fine, just startled because the kangaroo had a hold of him."

Mr Amor said the dog got away unscathed thanks to a chest plate, which usually protects them from boar tusks.

But as for the kangaroo?

"My mate only stunned it," Mr Amor said.

"His hand was OK, he didn't hit it very hard at all.

"It was funny because the guy who did it is the most placid bloke. We laughed at him for chucking such a sh*t punch."

Mr Amor said he hoped people would turn their attention to watching the DVD in full, which includes the footage of the kangaroo standoff.

"The DVD was released in newsagents last week so people can buy it," Mr Amor said.

Mr Amor said Kailem, who passed away last week, would be loving all the attention his trip was receiving.

"Kailem would be looking down from up there [heaven] and laughing because it was the highlight of the trip," Mr Amor said.

Kailem passed away last week, just days after marrying his girlfriend Brandi-Lee.

His journey and support has been documented via a GoFundMe page.