Australian authorities are investigating a US influencer who has sparked controversy by filming himself trapping wild crocodiles in Queensland.

Mike Holston is under fire for two videos posted for his millions of followers online – one showing him wrestling a freshwater crocodile, and another showing him manhandling a saltwater crocodile, one of the planet’s deadliest creatures.

Mr Holston says he made the videos for “educational purposes”, but wildlife experts say his behaviour is cruel and he’s been labelled a “goose” by the state’s leader.

Queensland officials say the influencer’s actions, which can attract fines of up to A$37,500 (£18,300, $24,776), are “extremely dangerous and illegal”.

In a video posted last week to his Instagram, Mr Holston – who goes by “The Real Tarzann” on social media – can be seen jumping into shallow water to chase a freshwater crocodile.

The animal draws blood before Mr Holston secures it, and can be heard calling out in the video.

“This is what dreams are made of,” the influencer says in the footage, adding that he had wanted to come to Australia since he was a child.

A second video shows Mr Holston heading into marshland to capture a juvenile saltwater crocodile. Usually one of the world’s most aggressive reptiles, the animal is largely limp as he holds it by the neck and lifts it for the camera.

In both videos, he can be seen releasing the animals back to the wild.

A spokesperson for Queensland’s environment department confirmed officials were investigating the incidents, which appear to have been filmed on the Lockhart River in Cape York.

“Let us be clear: people should not attempt to capture freshwater or saltwater crocodiles in Queensland, unless they are trained and licensed to do so,” the statement said.

On-the-spot fines of A$8,345 apply for anyone found to be interfering with a saltwater crocodile in Queensland, but penalties can climb to more than four times that in some cases.

The state government also introduced new legislation last year aimed at cracking down on dangerous crocodile interactions, which included making it an offence to unintentionally feed a crocodile by dumping food that attracts the reptiles to a public space.

While Mr Holston’s videos have been viewed – and liked – by masses of people online, there has also been growing condemnation of his actions.

Crocodile experts have expressed concern about the saltwater crocodile pictured in particular, saying it is unusual that it wasn’t thrashing about, trying to escape.

The father of the late Australian naturalist Steve Irwin has also weighed in, suggesting people like Mr Holston should be “booted out the door” if they don’t respect Australia’s wildlife.

Mr Irwin stressed the behaviour was far removed from the activities of his own son – who died in 2006 – aged 44.

“This isn’t a Steve Irwin issue. This is about an individual illegally interfering with protected fauna,” Mr Irwin said in a statement.

“Anyone who actually knows how to handle crocodiles knows they don’t respond well to capture. It’s a specialised skill to do it without causing dangerous stress and lactic acid build-up – and this bloke clearly had no clue.”

He said social media is playing a huge role in “glorifying” harmful wildlife interactions, and called for greater penalties for such behaviour – adding the current ones are “laughable” compared to the money that can be made off it online.

“These posts can have disastrous consequences for both people and wildlife.”

Mr Holston, though, has defended his actions. In a comment on the video of him handling the saltwater crocodile, he said the animal had been released “after a few up-close looks and photos”.

He said he did not “encourage anyone to try to recreate” the videos.

The outrage over Mr Holston’s videos comes just a few months after another US influencer was widely condemned for posting a video of her taking a baby wombat from the side of a road. She appeared to be laughing and running away from the distraught mother wombat.

Even Prime Minister Anthony Albanese waded into the discussion back in March, suggesting the woman, Sam Jones, do the same with animals that “can actually fight back”.

“Take a baby crocodile from its mother and see how you go there,” he said to her.

She left the country soon after anger erupted.