London - Rescuers battling Friday to save a 10-metre-long whale stranded on a mudflat off the south coast of England said the six-ton mammal had suffered kidney failure and would probably die if it swam out to sea.

The northern bottlenose whale was stranded for 12 hours in Langstone Harbour, in the southern county of Hampshire, before efforts succeeded to refloat it in shallow waters.

Rescuers said blood test showed that the whale was suffering from irreversible renal failure.

"If this animal does strand again the only humane cause of action will be euthanasia," said Faye Archell of the British Divers Marine Life Rescue organization (BDMLR). (dpa)