Japan's National Science Museum succeeded in filming the deep-sea creature at a depth of more than half a kilometre (a third of a mile) after teaming up 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 descend to the dark and cold depths of the northern Pacific Ocean, where at around 630 metres (2,066 feet) they managed to film a three-metre 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 kilometres (nine miles) east of Chichi island in the north Pacific.