The humpback whale, seen in the River Thames, was found dead east of London between Crayford Ness and the Queen Elizabeth II bridge, Dartford and will be autopsied, Reuters reported.
The 10m long whale was found dead in the shallows in Greenhithe, Kent, yesterday and was transported to London during the night.
The London Zoo will investigate the cause of the whale's death.
Up to 145 pilot whales have died in a mass stranding in a remote part of New Zealand, with authorities saying Monday they made the "heart-breaking" decision to euthanise dozens that lay stricken on the shore, reports AFP.
The stranding was discovered by a hiker late Saturday on Stewart Island, 30 kilometres (19 miles) off the southern coast of the South Island.
Over 150 whales were found dead on a beach in Australia, the BBC reported.
Animals of the type of tropical pilot were spotted by a fisherman at Hamelin Bay, about 300 kilometers south of Perth. Nearly half of whales have died, according to authorities in Western Australia.
A rescue action was organized to return the whales to the water with dozens of volunteers.