Humpback whale spotted in River Thames - BBC News
It is believed the whale - thought to up to 10 metres (33ft) in length - made a navigational error.
A humpback whale thought to be up to 10 metres (33ft) in length has been spotted in the River Thames.

It first surfaced in Dartford over the weekend and experts, who say it does not seem to be distressed, hope it will find its own way back to sea.

Ship pilots in the area have been told to proceed with caution.