Paul Jepson, of the Zoological Society of London (ZSL), who is an expert on whale and dolphin "strandings", hoped to find clues to explain why the 15ft northern bottle-nosed whale became lost.
Paul Jepson of the Zoological Society of London hopes to find clues which might explain why the 15ft northern bottle-nosed whale became lost in the capital's water course.
A spokesman for the charity group organising its rescue from the river in central London said the bottle-nosed whale went into convulsions as it was taken by barge into the Thames Estuary and died at around 7pm.
While the Thames may be home to a northern bottle-nosed whale for the first time since records began, the river has previously played host to a variety of unusual visitors.