At least 80 swans have been removed from the River Thames as part of a rescue operation following an oil spill that continues to baffle authorities.
Thames Water responded to calls at 10:30pm on Friday night to the stretch of river between Windsor Bridge and Eton Bridge.
Around 20 volunteers are working to remove the swans from the water and so far approximately 80 have been lifted out. Rescued swans were being pulled from the black water covered in oil reaching all the way up to their necks.
The Environment Agency is now investigating the cause of the spillage but said it is “quite unlikely” they will find the source due to most of the oil having dispersed leaving just isolated pockets.
Bob Lang, a volunteer at the charity Swan Lifeline, said he had seen many leaks in his 20 years at the charity but “nothing like this”.
“We have a set procedure. We have to get the oil off the feathers and then we dry them and let them preen themselves as much as they can”, Mr Lang said. “They have to be with us for a few days."
He added that swallowing oil can damage the swan's internal organs. “Whoever did it appears to have got away with it.”
A spokeswoman for the Environment Agency said a member of the public contacted them to report a “pollution in the river”.
The Environment Agency then reported this to Thames Water due to the possibility it was coming from the surplus drainage network.
The spokeswoman said: “There's no guarantee we'll find the source.”
Additional reporting by PA