Gilbert the whale is believed to have died after becoming trapped in netting
A whale spotted off the Dorset coast has died.
The northern bottlenose, which was given the name Gilbert, measured about 21ft (6.4m). The mammal was found dead on the beach at Alum Chine.
The young female, thought at first to be a male, was initially sighted on 13 September between Bournemouth Pier and Branksome.
Rescuers fear Gilbert may have got caught up in netting but post-mortem tests have proved inconclusive.
Further tests are needed to establish how the whale died, but it was revealed she had not been feeding.
Rope marks were discovered on her beak, prompting fears she had become tangled in nets.
The body will now be removed from the beach.
Gilbert was last seen in Dorset on Friday and there had been an unconfirmed sighting off the Cornwall coast. Conservationists had hoped she was making her way to the Atlantic.
Jenny O'Connor, from the British Divers Marine Life Rescue (BDMLR), said a bottlenose would normally be found off the west coast of England, migrating south at this time of year.
"I can't say for certain but it does look from the rope marks around her top beak that she may have been caught in some form of nets," she said.
"Obviously this has got to be looked into by the appropriate authorities and with the pathologists."
Gilbert was named after RNLI lifeguard Nick "Gilbert" Smith who first spotted her.
Rescuers said it was unusual to see a whale seemingly content to stay so close to the shore in an unfamiliar area.
It had been feared the mammal would become dehydrated feeding on small fish in the area, rather than its usual diet of squid, as it gets water from food.
Beach warden David Hubbard said: "I just heard it could be fishing nets which are fixed out in the bay.
"Unfortunately it is used to such deep waters, it has been caught in some shallow nets.
"Another reason might be it ran out of food because it is used to squid and the only thing we have out in the bay is cuttlefish."