The giant squid found floating off the Kaikoura coast on Sunday morning has been dissected and found to be a female.

The squid, measuring about eight metres in length, was found floating off the coast near Shark's Tooth at about 8am by Jack and Sharon Osikai, who were returning from a fishing trip. The couple, from Christchurch, have been holidaying in Kaikoura for about 20 years and said they had never seen anything like it.

Megan Bosch, marine biologist at the Kaikoura Marine Centre and Aquarium, took a scalpel to it in front of a crowd of people and a television crew on Monday evening.

She determined the squid was a female, partly because of its size - the female of the species is larger - and because she found a sac containing ovaries.

As previously suspected, the squid had been attacked by another, even bigger, squid, which was apparent by the markings of a beak larger than its own on its tentacles and mantle (body).

One of the squid's clubs (the two longest tentacles) which measured about 6.5m each, would be destined for Te Papa, she said. The Kaikoura aquarium already had a tentacle from another giant squid with which to compare it, she said.

The squid was probably swimming around the night before it died, Ms Bosch said. It was in perfect condition, other than the top portion of its mantle having been eaten off.

"It really does look like beak marks from another squid. They are carnivores, and they do eat each other," she said.

There was little evidence of the diet of the squid as its stomach contents were well-digested. The various parts of the deep sea creature will now be placed on display at the Kaikoura Aquarium for education purposes.

While the giant squid is not a common find, there have been plenty of sightings of smaller pieces of the creature in Kaikoura waters. A photograph of a giant squid on rocks at Oaro, south of Kaikoura, features in local literature, and fishermen Gus and Ken Garbes found one out at sea in 1972 near Rakautara, north of Kaikoura. However, when bad weather prevented them from towing it in, they settled for cutting pieces off to use as bait. Local beachcomber and shell collector Bev Elliott also recalls finding one on the beach around the peninsula some years back.

The giant squid is the second-largest mollusc and the second largest of all extant invertebrates. It is only exceeded by the colossal squid, which has hooks in its tentacles as opposed to the giant squid's barbed suckers. A squid has nine brains - one in its mantle and one in each of its tentacles.

News of the giant squid in Kaikoura comes less than one month after a Japanese film crew captured the first video of the elusive creature deep in the Pacific Ocean.

Japan's National Science Museum succeeded in filming the creature at a depth of about 630 metres in the Pacific Ocean and followed it in a submarine to a depth of about 900m.

Museum researcher Tsunemi Kubodera said the squid on the footage had its two clubs missing, and estimated it would have been eight metres long if it had been whole. Giant squid are thought to grow up to 10m long, but live at depths that humans generally can't explore, which is why so little is known about the species.