A passing tug saw the mammal, a young female humpback measuring around 36ft (11 metres) long, off the Isle of Sheppey in Kent.
Local navigation warnings were issued to vessels in the area to be aware of the floating carcass before it was towed to Sheerness Docks, Thames Coastguard said.
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The mother of a teenager from Kent, who died after taking the drug Fentanyl, is fighting for a change in the law.
She was a victim of childhood abuse. And when she summoned up the courage to report it, she was failed by police and abused by a teacher.
Helen has the latest forecast for the east of the region