There are fears that a shark three times bigger than the Great White could really be lurking deep in the ocean, following the release of Hollywood blockbuster The Meg.

The film's focus is on a giant, terrifying prehistoric shark believed to be extinct, that has emerged to the water's surface to torture swimmers, sailors and surfers.

In the movie, starring Jason Statham, he and his marine biologist team try to kill the 75-foot long monster in a battle that involves everything from grenades, knives, helicopters and mini-submarines.

However, following the film's release a couple of weeks back, movie goers are wondering if the giant shark is based on a real creature – and if it still exists today.

The megalodon, whose name means big tooth, was indeed real and could accommodate 270 teeth in its mouth.

Experts at the Natural History Museum estimate that its bite would span 9 foot by 11 foot – enough to swallow a family car, according to the Daily Mail.

The creatures are thought to have become extinct some two to three million years ago, due to climate change.