A 44FT sperm whale which became beached probably died because it got lost, a marine expert involved in the rescue bid said today.

The 20-tonne adult male was stranded on Redcar beach in Cleveland and reported to police at 6.10am, sparking a major operation to save it.

But Richard Ilderton, of the British Divers Marine Life Rescue, who was called to the scene, said the North Sea was the wrong environment for such a large creature, and any attempt to refloat it - even if it was possible - would have been cruel.

The partially-submerged whale was pronounced dead shortly after 9am, despite firefighters keeping it wet with a jet.

Mr Ilderton said: "While we have whales in the North Sea, it is not a suitable environment for a sperm whale because the food supply is not there.

"It doesn't eat, it becomes malnourished, it becomes dehydrated because whales do not drink - they get their liquid from their food.

"It can cause all sorts of health problems and ultimately results in something like this happening."

He said rescuers can refloat whales of up to five tonnes, but this specimen was four times heavier.

"If we were able to put the animal back out to sea, all we would be doing is putting it back out to starve, which is massively cruel and against what we want to do," he said.

"Although it has died, this has been the better option."

Hundreds of people came down to the beach to take in the spectacle.

Martin Unne, 58, from Thirsk in North Yorkshire, was among the many enjoying the half-term sunshine who came to see the whale after hearing about its plight on the radio.

"This is a once-in-a-lifetime opportunity," he said.

"It would be more interesting if it were still alive, so it is sad it is not.

"Nature is amazing."

Steve Goldswain, responsible on Redcar and Cleveland Council for community protection, said cordons were put up as it could be a health hazard.

The whale will remain on the beach overnight, watched by security guards, before a post-mortem examination is carried out by zoologists tomorrow.

As well as the police, council, firefighters and rescue divers, the RSPCA and Coastguard were involved.

Mr Goldswain said: "From an environmental perspective, we need to keep the beaches clear.

Obviously a dead animal poses some health risks to the community and we need to minimise that risk."