The first stranded Orca in England and Wales since 2001 has been found by the Zoological Society of London (ZSL).
The 15ft (4.5m) long juvenile male killer whale was discovered in the Wash on the coast of Norfolk and Lincolnshire.
ZSL said it was likely the whale died a few weeks ago and it has taken blubber, liver, muscle and kidney samples.
Researchers also found a large fragment of plastic in the whale's stomach, but it was not the cause of its death.
Orcas are a priority species for research by ZSL as they are top predators that can absorb significant concentrations of marine pollutants.
The team also collected teeth to accurately age the animal and said genetic analysis will help determine which population the animal came from.
Experts said there was no evidence of recent feeding as its stomachs were largely empty.
ZSL said: "As this is such a rare case, subsequent analysis will inform UK marine mammal research for years to come."