Police are investigating an allegation of rape after a woman said she was assaulted in a park in the early hours of Sunday morning.
The woman, reported to be in her 20s, told police she was assaulted by a man in parkland near Victoria Road, Colliers Wood, at about 2.30am on July 8.
No arrests have been made.
Neil Malcolm, of Lavender Fields residents association, said police closed the path running from the end of Victoria Road to the Tandem Centre in Tandem Way all day on Sunday.
He said: "At about 5.30pm the area was still closed and about a dozen people were clearing the dense undergrowth adjacent to the pond as if searching for evidence."
The footpath is understood to be the route of the former railway line.
Officers from Operation Sapphire, who are specially trained to investigate crimes of a sexual nature and support victims of crime, are investigating.