[Photo] The squid is thought to be the largest specimen ever found

An industrial-scale microwave oven may have to be used to defrost a colossal squid caught in the Antarctic last month, scientists say.

They are pondering how to thaw out the half-tonne squid in a way that makes sure none of it rots before other parts have defrosted.

The squid has been kept frozen since it was caught by New Zealand fisherman in deep Antarctic waters in February.

Scientists want to preserve the unique specimen for detailed study.

Squid expert Steve O'Shea said the Mesonychoteuthis hamiltoni measured 10 metres (33ft) in length.

It weighed 495kgs (1,089lbs), heavier than an initial estimate of 450kgs (990lbs).

Mr O'Shea said it would take days for the colossal squid to defrost at room temperature - meaning its outer flesh could have rotted by the time the centre thawed.

He said a massive microwave was one option.

"There are certain microwave equivalents that are used by industry, for treating timber and the like, that we could probably fit this thing into," Mr O'Shea, of Auckland University of Technology, said.

Museum display

The fishermen were fishing for Patagonian toothfish in deep Antarctic waters when the squid - which was eating a toothfish - was caught in mid-February.

It took them two hours to reel in the huge creature.

The squid was frozen in the ship's hull and brought back to New Zealand for examination.

Scientists believe it is by far the largest specimen of the colossal squid ever caught.

At the time of its arrival, Mr O'Shea said calamari rings made from it would be like tractor tyres - although would taste of ammonia.

The squid is currently being kept at New Zealand's national museum, Te Papa Tongarewa, in Wellington.

Museum officials hope to embalm the squid and put it on display, while giving scientists access to study it.