One of the biggest "fatbergs" ever seen in Britain, a ball of fat as long as three soccer pitches, is seen after it was found blocking a Victorian-era, east London sewer, in an image handed out by Thames Water, September 12, 2017. Thames Water handout via REUTERS

LONDON (Reuters) - One of the biggest “fatbergs” ever seen in Britain - a ball of fat as long as three soccer pitches - has been found blocking a Victorian-era, east London sewer.

“It’s a total monster and taking a lot of manpower and machinery to remove,” said Thames Water’s head of waste networks, Matt Rimmer. “It’s one of the largest we’ve ever seen.”

The rock-solid mass of wet wipes, nappies, fat and oil weighs as much as 10 double-decker buses.

Work in Whitechapel to remove the blockage started this week and involves an eight-strong crew using jet hoses to break up the mass before sucking it out with a tanker.

“It’s basically like trying to break up concrete,” said Rimmer. “It’s frustrating as these situations are totally avoidable and caused by fat, oil and grease being washed down sinks and wipes flushed down the loo.”

“Bin it, don’t block it” was the message, he added.

Four years ago a similar but smaller fatberg was found in a sewer in Kingston, southwest of London.