大象传媒

London's canals are normally a quiet haven in the centre of the capital, but now a stretch of the longest one, is covered in a thick yellow greasy scum.

Experts believe a large section of the Grand Union Canal has been deliberately polluted with dumped cooking oil.

It has been declared a category 3 incident by the Environment Agency, which means the clean up operation falls to the charity Canal and Rivers Trust.

It estimates that costs will mount up to 拢10,000 a day.

大象传媒 London's Transport Correspondent Tom Edwards has the story.