A team of researchers have discovered what is believed to be the world's deepest living animal, a species of nematode or roundworm, according to a new study published online in Nature.

Halicephalobus mephisto, which is named after devil Mephistopheles as it inhabits deep, was discovered at a gold mine in South Africa almost one mile below the ground, the study published on June 2 said.

"It's like 1 million times the size of the bacteria it eats—sort of like finding Moby Dick in Lake Ontario," said co-author Tullis Onstott at Princeton University in New Jersey.

The deep subsurface biosphere that goes about 2 miles deep into the ground is one of the most difficult place to survive with temperature, oxygen and space constraints. However, the scientists were able to discover four species of roundworms during their underground study.

Gaetan Borgonie at Belgium's University of Ghent told Nature said that looking into the deep underground was a complete 'out of the box' idea.