WELLINGTON, NEW ZEALAND - THE biggest squid ever caught, at up to 10 metres long and boasting a fearsome beak and razor-sharp hooks, may be small compared with others still lurking in the depths, scientists said yesterday.

The colossal squid has begun a two-day thaw at The Museum of New Zealand in Wellington before it is examined in more detail today by scientists.

It weighs 495kg, has eyes the size of dinner plates and is estimated at up to 10m long.

On a museum blog following the progress of the thaw, Chris Paulin - who is projects manager at the museum, known as Te Papa Tongarewa - said yesterday that the beak has been exposed as the flesh defrosts.

The size of the lower beak - used to chop prey into bite sized pieces - is around 43 to 45mm.

Colossal squid lower beaks previously found in the stomachs of sperm whales have been as long as 49mm.

Extrapolating the relationship between the length of the beak and body size from another smaller specimen being examined suggests it could grow much bigger, Mr Paulin said.

"Can we assume that this species reaches three quarters of a tonne in weight?" he asked.

One of the scientists leading the examination, Auckland University of Technology squid expert Steve O'Shea, said it was difficult to say how much bigger it could grow.

"What we know from that one measurement is that the beak of this animal from the stomachs of sperm whales are
considerably larger," he said.

"We make the leap to say the colossal squid grows considerably larger than the 495kg one we are currently defrosting."

If the new specimen was cut into squid rings, they would be size of tractor tyres, although they would taste like ammonia.

It was caught as it ate an Antarctic toothfish hooked on a fishing boat's line in Antarctic waters in February last year.

After being snap frozen, it was given to the museum, which has since been deciding the best way to defrost, examine and display it. --AFP