Engineers' efforts to fix a fat-damaged sewer in the Thames Water network are being hampered by tonnes of fresh grease - despite their impassioned pleas to "Bin it - don't block it."

Last month Thames Water had to deal with the 15-tonne ‘fatberg’ that caused the sewer pipe to collapse

Gordon Hailwood, Thames Water contracts supervisor, told how the troublesome berg had been caused by cooking fat and wrongly-flushed wet wipes. Puzzled by the emergence of fresh fat oozing from the same sewer, he said:

“This sewer pipe collects the sewage from across most of Kingston so it could be coming from anywhere. Old, congealed fat is white, but this was yellow in colour, so it’s been put into the sewers over the last few weeks.

“We’ve spent a lot of time drawing attention to the dangers of putting fat down the drain, so I can’t imagine where these huge amounts are coming from.”

Thames Water now plans to write to homes and businesses to underline the seriousness of the problem. The company spends £1million every month dealing with blockages caused by fat and wrongly flushed items.

Hailwood and his team have also discovered further damage in the trunk sewers in the London Road area - the team will need to extend the work to put it back in working order.

Gordon Hailwood said that the weight of the fat in the pipes had pushed the sewer pipe down into the soft subsoil and that brick sewers would need to be replaced with newer more robust pipes. No end date has been given for the work yet while investigations to assess the condition of the sewers continue.