Swans have been left coated in oil after a serious oil spill on the River Medway.

Swan's Sanctuary rescued 50 of the birds along with some geese after the incident near Hampstead Lock in Yalding, near Maidstone.

The charity from Felix Lane, Shepperton, Middlesex rushed out to help rescue the swans.

Spokesman for the charity Steve Knight said: "They will need to be cleaned, fed, medicated and housed over the coming weeks until they are ready to be returned to Kent once the Environment Agency can assure us that the River Medway is in a fit state."

The spill was treated as a Category 1 pollution incident, which is the most serious.

The EA set up temporary floating barriers known as 'booms' in an attempt to reduce the area affected.

Investigations on what caused it are still ongoing but there are concerns oil was "illegally dumped".

The swan rescue charity is critical of how the situation was handled.

Mr Knight said: "We thought the oil had been contained at Hampstead lock to protect the wildlife. It wasn't contained very well for a Category 1 spill."

"We had to carry out a Category 1 wildlife rescue as far down as East Farleigh."

A spokesperson from the government body said: “ The Environment Agency officers have been working with specialist contractors throughout the weekend to clear up as much oil as possible.

"Hampstead Lock will remain closed to navigation until the clear up operation is completed which we expect will take another day or two. We believe that the oil was illegally tipped into a drain in the vicinity of Yalding Station sometime on the morning of Friday February 11."

The sanctuary were aided by members of the public in rescuing as many swans as possible.

Mr Knight added: "Because there were so many contaminated birds one of the local residents helped with transporting them to the hospital.

"It has been a bit of a mammoth task and this all has a huge cost as you can imagine.

"All the ambulances sent from the sanctuary are owned, maintained and fuelled by the charity. Our staff that attended are all employed by the charity. All vehicles will have done about a thousand miles on this one incident."

The charity receives no government funding and relies solely on donations form the public.

Anyone wishing to donate can do so by direct debit to The Swan Sanctuary; Sort Code 60-07-33 Account No 89249119 or online or by post to the address below all payments should be made payable to The Swan Sanctuary. Charity number 1002582.

Anyone who has any information that can help in the Environment Agency's investigation is encouraged to call their free 24-hour Incident Hotline on 0800 80 70 60.