Japan's National Science Museum succeeded in filming the deep-sea creature in its natural habitat for the first time, working with Japanese public broadcaster NHK and the US Discovery Channel.

The massive invertebrate is the stuff of legend, with sightings of a huge ocean-dwelling beast reported by sailors for centuries.

The creature is thought to be the genesis of the Nordic legend of Kraken, a sea monster believed to have attacked ships in waters off Scandinavia over the last millennium.

Modern-day scientists on their own Moby Dick-style search used a submersible to get them into the dark and cold depths of the northern Pacific Ocean, where at around 630 meters they managed to film a three-meter specimen.

After around 100 missions, during which they spent 400 hours in the cramped submarine, the three-man crew tracked the creature from a spot some 15 kilometers (nine miles) east of Chichi island in the north Pacific Ocean.

Museum researcher Tsunemi Kubodera said they followed the enormous mollusc to a depth of 900 meters as it swam into the ocean abyss.