Police say a "distressed" girl who claimed to have been sexually assaulted in Plumstead at the weekend was aged just 12.
Officers were called to Marmadon Road at 4.30pm on Sunday (june 15) and found the girl, who said she had been assaulted in nearby Plumstead Gardens.
Part of Plumstead Gardens remained cordoned off this morning while an officer stood on duty.
Officers from the Met's Sexual Offences, Exploitation and Child Abuse Command are investigating but there have been no arrests so far.
Anyone with information should call the incident room on 020 8721 4653 or, to remain anonymous, call Crimestoppers on 0800 555 111.