Officers are investigating what they say are a series of linked sexual assaults in the Penge area.
All the reported incidents follow a similar pattern, with women approached by a lone male who sexually assaulted them before fleeing the scene.
None of the women were physically injured during their ordeal.
The first reported assault took place on February 9, on High Street.
It was followed by cases on Feb 15, at Penge East Station, February 16, at Evelina Road, and incidents on Royston Road, Clevedon Road and Franklin Road on February 20, 23, and 28.
Police arrested a fourteen-year-old boy on suspicion of sexual assault who has now been released under investigation.
Anyone with information, or who believes they may have been targeted by the perpetrator, should call 101.
To give information anonymously, call Crimestoppers on 0800 555 111.