Scientists are testing samples from the whale

Rescuers failed to save the 36-foot-long mammal after it was discovered on a sand bank near Sutton Bridge.

Dr Paul Jepson, who carried out a post-mortem examination, said scientists were trying to determine what caused the whale to die.

Experts have speculated the 15-tonne whale could have become confused.

Collapsed lungs

Dr Jepson said: "It would be impossible to dispose of the carcass, so it will just decompose naturally.

"It may actually wash away on the high tide," he said.

The whale was spotted by a member of the public at about 1000 GMT on Sunday.

It is believed the animal might have become stranded due to ill health, or been confused by the sand banks and shallow water of the The Wash.

Volunteers spent Sunday trying to keep the whale upright so its lungs did not collapse under its own weight.

Inspector John Bowe from the RSPCA said: "It was a deepwater animal and shouldn't be there; it had obviously lost its way."