Graphic video shows moment a massive croc attacked a dog

Graphic footage of a giant croc stalking two dogs and then launching an attack is circulating on social media, but its origin is so far unknown.

In what has been described as a family video filmed near Weipa, two dogs are seen wading near the water's edge as a half-submerged crocodile stalks and approaches in the background.

A woman's voice is heard in the video trying to call the dogs away from the water, to no avail. Other voices - including distressed children - are heard as the croc gets gets closer to one of the dogs.

Watch and listen to the video below.

Tropic Now is attempting to verify the creator of the video, and it remains unclear where and when the footage was taken.