A brutal film on the culling and commercial exploitation of kangaroos, labelled a misleading "beat-up" by farmers, has sparked an all out war between activists and those involved in kangaroo management.

With 45 million kangaroos in Australia they are hardly facing extinction, but the controversial new film Kangaroo: A Love-Hate Story tells a very different story.

Greens senator Lee Rhiannon is in Brussels this week to speak at the European premiere of the film along with activists.

But the National Farmers Federation, a leading environmental professor, and meat processors have all slammed the film as a misrepresentation of the situation, that ignores the basic facts.

The animal activist movie suggests kangaroos are a "disappearing resource", and shows footage of the animals being shot en masse and taking bullets to the head.

It attempts to provide balance with a shooter talking about the industry code of conduct, but focuses on him saying they have to take the animals out with a "brain shot", which is not always easy to do, and that they cannot cull females with young.

There is a strict Federal Government code of practice for the humane shooting of kangaroos with outlines method of shooting and how to deal with injured kangaroos and their young.

Federal Agriculture Minister David Littleproud said Senator Rhiannon's promotion of the film is "absolutely disgusting", and only 3 per cent of the Kangaroo population was harvested.

It is illegal to kill a kangaroo without a federal permit, and anyone caught can be fined up to $10,000.

The documentary has been screening in the US and Europe for more than a month, prompting claims of an animal-welfare "crisis" in Australia.

Film 'exposes a wildlife massacre': New York Times

The film was made by Bondi filmmaker Michael McIntyre and co-director Kate McIntyre Clere.

They were at the sold-out premieres in New York and Los Angeles.

McIntyre told journalists kangaroo culling was a "deep dark secret".

"Part of the reason we are premiering in America and not Australia is that the Americans are the second largest consumers on kangaroo body parts."

The movie has been reviewed in the some of America's major publications.

The New York Times said the film "exposes a wildlife massacre", while Variety called it provocative "eco-activist filmmaking".

The Hollywood Reporter described it as a "heartfelt defence of a cute, inspiringly odd creature outsiders might assume needs no such defence."

'Misleading and damaging to Australia': Farmers

President of the National Farmers Federation (NFF) Fiona Simson said the organisation was very concerned the film was "quite misleading and very damaging to Australia," she said.

"There is a lot of misinformation around kangaroos and how we treat kangaroos in Australia.

"This is an issue we need to address very calmly and need to make sure we keep facts on the table when talking about something so dear to Australia as kangaroos."

She said since 2010 kangaroo numbers had increased "exponentially" to nearly 50 million, and film was using shock tactics.

She said people in the bush thought the film was a "complete joke", and that hard questions needed to be asked about the filmmakers' motives.

"I hope it does not damage the industry, I think kangaroo meat industry bring $200 million-plus into regional Australia [and] employs more than 2,000 people."

Australian National University School of Environment Professor Dr George Wilson said culling was a numbers game the filmmakers had ignored.

"It's a complete own-goal by the people that have made the film.

"The thing that affects kangaroos, of course, is overpopulation, and populations go up during good seasons and then come back down again during droughts.

"If they're successful in shutting down the kangaroo industry, which has been partially effective at the moment, then these kangaroo populations will rise even higher and crash even more.

"That's not a good situation for the kangaroos, either individually or as a population, nor is it a good thing for our grazing landscapes."

Kangaroo industry furious at 'beat up'

Kangaroo Industry Association of Australia president Ray Borda vented his anger from the Tokyo Game Fair.

"Everybody knows there's millions of Kangaroos in Australia, and they're in a lot of areas in plague proportions," he said.

"The Kangaroo Management Program's been set up for the commercial industry because of overpopulation.

"There's 60 species of kangaroos and wallabies, but the commercial industry only takes four of those.

"Of the four of those, the most abundant, there's an estimated 45 million adult kangaroos."

He said there was no danger of kangaroos being hunted out of existence.

Concerns for future of roo meat industry

The industry is concerned the nation's $200 million kangaroo meat industry could be damaged by the film.

Betty Mickelbourgh from Surat in south-west Queensland has worked in the kangaroo industry for as long as she could remember, and said she was devastated about the film.

Ms Mickelbourgh owns processing plant Warroo Game Meats, which employs 25 to 30 people.

"It'll have a big impact on us … it is very serious.

"People out there have got to be accountable for shutting our business down because that's what will happen.

Mr Borda said the film will cause a bit of confusion.

"Most people around the world now have access to the internet and … know exactly how many kangaroos there are, the overabundance of it," he said.

"It's all scientifically surveyed, it's been surveyed for 30 years, the truth is we come under most criticism because we don't take enough because we can't even keep up with the birth rate."

Senator Rhiannon has been contacted for comment.