A group of men surrounded a lone women outside a south London Tube station and sexually assaulted her, police have said.
British Transport Police has released an image of a suspect following the attack outside Stockwell station.
It happened at about 3.20am on Saturday. The woman was surrounded by the men in the entrance of the station.
Two of them grabbed and sexually assaulted her.
One of the men was arrested at the scene by officers, but they are also looking to identify the man in the CCTV image.
Anyone with information is asked to call 0800 40 50 40, quoting reference 80 of January 27. Alternatively, call Crimestoppers anonymously on 0800 555 111.
