Gallons of sewage water have gushed into streets in Coulsdon, trapping people in buildings.

The filthy liquid is causing a "very strong sewage smell" to waft over the area, social media users reported.

A block of flats near Coulsdon South station in Hadley Grove was said to have been flooded, with occupants trapped inside by the surrounding sea of sewage.

UPDATE 3.20pm: A Thames Water spokeswoman said this morning's sewage leak had been caused by a "problem with a valve which controls the flow of sewage through the pipes", which had since been resolved.

She added:"We've got a tanker there pumping away the waste water and a team clearing up the affected area.

"This work will continue throughout this afternoon."

Jacqui Lyseight wrote on Facebook: "Newish flats next to the station have flooded with sewage. People are trapped in there as the whole building is surrounded and it's deep!"

Some people said the smell was so strong they could "hardly breathe".

Tim Coombe said: "I think it's from that big sewage tank they put under Reddown Road when they built the new flats. They don't remember to empty it so this happens every year or so. Even more revolting than usual this time!"

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Photo: Jacqui Lyseight

A staff member at nearby Poppy Cafe, in Coulsdon Memorial Ground, said he had not been aware of the sewage leak of this morning.

But he added: "There's been a sewage problem down here for yonks. I think it's something to do with the train line and the river."

A spokesman for Thames Water said: "We have a team booked to investigate reports of sewer flooding in the flats behind Coulsdon South station as a priority.

"We’ve cleared a blockage there before, which had been caused by a build-up of cooking fat and wet wipes – and which should never be flushed."

He said they hoped to be "able to clear the sewer and get everything back to normal quickly".

Ms Lyseight, whose son lives in the block of flats marooned by the sewage, said a team from Thames Water have been pumping sewage from the area since 10.30am.

Croydon Council has also been contacted for comment.

Speculating on the cause of the sewage leak, one social media user pleaded: "Hope it's not nappies wet wipes etc........people still do it!!”

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