A new artificial reef has unintentionally been created near Fraser Island after a four-wheel-drive rolled off the back of a barge transporting people from the island to River Heads.

In a video uploaded to Moreton Crime Watch, the Toyota Land Cruiser can be seen rolling off the back of the barge.

None of the other vehicles move, suggesting the handbrake was not in use.

The barge then powers away as the four-wheel-drive sinks in its wake.

"Luckily nobody inside the car! But quite a few phones, debit cards, passports and valuables all gone," Chloe, the person credited with filming the video, said.

Many commenters on Facebook are sceptical as to how the vehicle would have simply rolled off the back of the barge.

"The sign says 'put your vehicle in gear with the handbrake firmly on' on most vehicular barges," Brad Pryce-Davies wrote. "Lesson learnt hard."

Others question whether the Land Cruiser was allowed to drift off the boat intentionally.

"No accident. Deliberately done. Insurance job," Shareith Newsom suggested.

"What's with the bloke just watching it roll off? Surely make a small attempt to chock the wheels. Very suss. (Lucky no sleeping baby in there tucked up in their booster seat)," Andrew Lauren Thomson commented.

The video's uploader suggests the four-wheel-drive is now 60m underwater.