WELLINGTON, NEW ZEALAND - THE largest squid ever caught began to reveal its secrets on Wednesday, including eyes the size of beach balls that one scientist said were likely the biggest ever known in the animal kingdom.

The 495kg colossal squid - accidentally caught by a fishing boat in Antarctic waters in February 2007 - is slowly thawing under the fascinated gaze of a team of scientists at the Museum of New Zealand.

While the defrosting was taking longer than expected on Wednesday, one of the earliest revelations were eyes measuring 27cm across - about 11 times the size of a human eye - with lenses of 10 to 12cm in diameter.

Those figures are based on the current collapsed state of the eyes.

If the squid were alive, said Professor Eric Warrant of the University of Lund in Sweden, the eyes would probably measure about 40cm across, 'about the size of a beach ball.'

'These are without doubt the largest eyes that have ever been studied and probably among the largest eyes that have existed during the history of the animal kingdom,' he wrote in a blog on the Wellington-based museum's website.

These would help the squid to locate prey in the dark of its habitat 1,000m or more below the surface of Antarctic waters.

The exact dimensions of the squid will not be determined until it is fully defrosted later on Wednesday but it was believed to be eight metres or more in length.

Two long tentacles carry up to 25 rotating hooks each and eight arms each contain up to 19 hooks used to capture prey and bring it to its beaked mouth.

The sex of the squid was still to be determined, although it was thought likely to be a female, which grow larger than males.

But Mr O'Shea and his colleagues believe that larger squid still lurk in the southern ocean depths.

The squid's lower beak measures around 40cm across, while other beaks have been found - usually in the stomach of predator sperm whales - measuring up to 49cm.

Mr O'Shea said it is possible that colossal squid (Mesonychoteuthis hamiltoni) may grow to up to 750kg but there was not yet enough information to be sure.

'When I said in 2003 that colossal squid could grow to 500kg no one believed me, I was ridiculed, people laughed at me,' he said.

The progress of the thawing is being shown live by webcams on the museum's website at www.tepapa.govt.nz'>http://www.tepapa.govt.nz'>www.tepapa.govt.nz. -- AFP