HS2: Foam pool appears near construction site in west London

A pool of brown bubbling foam has appeared where work to build the HS2 high speed rail line is being carried out.

The five metre (16ft) "mini geyser" on a rugby pitch in Ruislip, west London, is near to where some of the tunnelling work is being carried out.

Work was briefly halted over the weekend to investigate the cause.

HS2 say the borehole leak causing it has now been sealed and it will monitor the situation.

Residents and campaigners have raised concerns over potential toxins seeping into the earth during its ongoing construction.

Sarah Green, from the Hillingdon Green Party, said along with residents, she feared a carcinogenic chemical, chromium-6, was being leaked into the environment.

A HS2 spokesperson said: "Upon discovering the small pool of foam in Ruislip, HS2's main works' contractor SCS sealed off the area to investigate.

HS2 fenced off the foam and installed "danger" signs on Sunday

"The pool appears to have come out of an pre-existing borehole, causing foam to travel up and pool on the surface.

"The area is safe, the leak has been sealed, and the foam has been cleared. There has been no impact on the programme schedule."

HS2 added Ruislip Rugby Club was not impacted by the the borehole as it sits far away from the pitch and close to the land boundary.

The foam had visibly gone by Monday morning.

Follow BBC London on Facebook, Twitter and Instagram. Send your story ideas to [e-mail]