Media playback is unsupported on your device

Fatberg plague: BBC gets close-up look

25 April 2014 Last updated at 07:50 BST

Huge lumps of oil and grease caused by pouring hot fat down the drain are costing water companies around £79 million a year to tackle.

The BBC's John Maguire takes a close look at "fatbergs", which are causing problems in London's sewers.

Copyright © 2015 BBC. The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.