Scientists have captured footage of an elusive giant squid, estimated to have grown as large as eight metres long, that roams the depths of the Pacific Ocean.

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 America's Discovery Channel.

Up close ... the 8-metre squid. Credit: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 past millennium.