Detectives are renewing appeals for witnesses to an assault outside Waterloo Station at the end of last year which left a man in a critical condition.
An image and CCTV footage of a man police wish to identify has also been released as officers ask for anyone with information to come forward.
Detective Constable Alex Atkinson, said: "Four months on, the victim remains in hospital where he is receiving ongoing medical treatment for life-threatening injuries.
"We have carried out extensive enquiries to locate the man who was captured on CCTV fleeing the scene of this cowardly attack. Due to the location, it is possible that the man lives outside of London and may commute via Waterloo.
"Do you recognise him or the description of his clothing? I am also yet to hear from the woman who was at the scene.
“I would urge anyone with information to contact us."
At approximately 23:00hrs on 1 November 2018, the victim - a 27-year-old man - was seen standing at the bottom of the steps of the main entrance to the station (Victory Arch) asking for cigarettes from members of the public.
He appeared upset and was seen crying, although he was not causing any concern and appeared harmless.
A female member of the public appeared to take offence at the man asking for cigarettes and began shouting at him.
The man then approached and an argument ensued between the victim and this suspect. The suspect walked away from the station entrance and onto Mepham Street with the victim following behind. The pair stopped and the victim was punched in the face. The assault caused him to fall backwards and hit his head on the floor.
The suspect ran off through the adjacent archway and crossed the road towards the Imax cinema.
The London Ambulance Service and officers attended shortly afterwards and the victim was taken to a south London hospital. He remains in a critical condition.
The suspect is yet to be identified. He is described as a white man, aged between 20 and 30 years old, 6ft 2ins tall, of large stocky build, with short cropped fair hair and clean shaven.
He was wearing a bright red Adidas jacket/hooded top with a white logo in the middle, blue jeans and white trainers. He was carrying a black gym bag. He spoke with what has been described as a 'southern English/cockney accent'.
Anyone who recognises the man is asked to call officers at the Central South Command Unit - based at Walworth police station - via 101 quoting reference 8498/01Nov18 or Crimestoppers anonymously on 0800 555 111.
You can also tweet police via @MetCC