Police have released CCTV after a man was pushed onto the tracks at Stockwell station.
Officers said two men were seen having a conversation, before the suspect punched the victim and pushed him onto the rails.
The victim, aged in his 50s, was then helped back onto the platform by a friend after the incident at 2.30am on Sunday 30 June.
The British Transport Police have issued a CCTV image of a man in an appeal to find out more information about the incident.
He was wearing a cap, dark sunglasses, a checked shirt and a gilet.
Anyone who recognises him is asked to contact BTP by texting 61016 or by calling 0800 40 50 40 and quoting reference 72 of 30/06/2019.
