Worrying footage of children playing dangerously close to crocodile-filled waters has been shared online by a leading authority.

David McMahon works as a naturalist safari tour guide with Venture North Safaris. He's been leading expeditions into some of the wildest parts of northern Australia for over 16 years and has worked with and around crocodiles both captive and in the wild.

Right now though, McMahon is concerned. His concerns center on the behavior of many visitors at the infamous Cahills Crossing on the East Alligator River.

Located on the border between Kakadu National Park and Arnhem Land in the remote top end of Australia's Northern Territory, though it may be known as the East Alligator River, it's actually teeming with crocodiles rather than alligators.

That's something McMahon explains is because "the Brit who named it didn't know the difference" between the two species.

This is no laughing matter though. Instead, McMahon is drawing attention to the area for altogether more serious reasons.

"I posted this video to highlight some of the unbelievably reckless behavior I've been witnessing of late at the river and I hope that with a bit of shaming people stop and take notice before someone gets eaten by a crocodile," he told Newsweek.

In the clip, several adults can be seen fishing close to the edge of the water while saltwater crocodiles are visible swimming in close proximity. More concerning still, a handful of kids are seen sitting on rocks near the water's edge or playing nearby.

McMahon is right to urge visitors to exercise caution.

Back in July, a 12-year-old girl went missing after swimming in a river named Mango Creek in Australia's Northern Territory, some 220 miles southwest of the city of Darwin.

Her remains were eventually recovered and showed injuries consistent with a crocodile attack.

"Saltwater crocodiles are the most dangerous crocodile in the world and given the opportunity won't hesitate to take a person," McMahon warned.

He's keen not to spread too much panic, but wants people visiting the region to take sensible steps to avoid any potential danger.

"They're patient [saltwater crocodiles] and they don't need to eat often so if you stay a couple of meters back from the water you're absolutely safe! It's that simple."

While McMahon is keen to avoid any tragedy, his warning is also about keeping the crocodiles that live there safe too.

"The problem is that this river is full of hundreds of crocodiles as it has been for millions of years but if someone gets eaten then crocodiles get shot as a consequence," he said. "It's not their fault but they end up on the chopping block because people can't read a sign and use a bit of common sense."

Ultimately, he believes it's crucial to protect the region's crocodile population. "Without them the system loses its balance and we need to work with them to keep the bush healthy," he said. "We need to keep educating people on how easy it is to stay safe around crocodiles to prevent another fatality."

He added: "If you find yourself face to face with a crocodile you've done something very wrong! Always stay a few good meters back from the water in croc country and presume all water in northern Australia has crocodiles unless there are signs saying you can safely swim. It's really that easy!"