This is the moment a massive 16-foot anaconda wraps its coil around a wild pig in the crystal-clear waters of a Brazilian river and begins to swallow it whole.

The frightening footage shows the huge aquatic snake wrapped around the helpless hog as it slowly squeezes the life out of it.

Underwater video footage shot by a wildlife fan shows the snake pulling the pig to the riverbed where it drowned.

Anacondas can go for 10 minutes underwater before they need to take a breath, say experts.

As the pig stops moving, the 16-foot snake’s coils spin around as its huge jaws open up to begin gulping down the entire pig from the snout down.

Tour guide Celio Araujo, 42, shared the footage after capturing the moment on the Sucuri River in Bonito, in the state of Mato Grosso do Sul, at around 2 pm on 18th October.

Araujo had been leading a tourist group when he noticed a spooked monkey just before stumbling across the snake devouring its prey.

The tour guide returned to film this incredible moment after dropping off the tourist group.

Araujo explained: “When I filmed her, she had already strangled the pig, and already killed it.

“I said: ‘I know her’ because I always see her there.”

He explained that most tourists are scared of anacondas, but he said: “The animal will never attack a person unless the person provokes it.”