Homes in south London had to be evacuated last night as a river of brown, murky water swept through the area. Initial reports suggested a sewage pipe had sprung a leak.

Twitter was awash with photos of the 'river of poo' on Clapham Road near Oval station in Kennington. Toilet humour abounded using the Twitter hashtags #londonpoo and #poonami.

A Thames Water spokesman later pooh-poohed the sewage theory, saying the incident was caused by a burst water main, mixed with silt and mud.