Police want to trace a brave passenger who put his life in danger to jump onto live Tube tracks and pull a man to safety.
Just before 5pm on Tuesday a 47-year-old man was standing on a northbound Northern Line platform at Tottenham Court Road Underground station when he suddenly became unwell.
He stumbled on the platform and fell onto the live tracks - prompting an unknown bystander to jump onto the live rails and pull him safely back onto the platform.
The man was treated by paramedics at the scene before being taken to hospital. Officers said they have since been told he received light cuts and bruises and will make a full recovery.
Praising the work of the bystander, Superintendent Chris Horton, of British Transport Police, said: "Going onto the tracks is extremely dangerous but the bravery of this man has to be praised.
"The man sprung to the rescue and hauled him back onto the platform, whilst other commuters alerted the emergency services.
"Whilst the approaching train was immediately put on a red signal, the quick thinking of him and other passengers on the platform avoided what could have been a tragedy.
"On behalf of everyone at British Transport Police, I'd like to commend this man for his brave actions - his quick thinking most likely saved the man's life."
Police want to find the rescuer and recognise him for his courage.
A spokeswoman from the London Ambulance Service said medics were called to the incident at around 5.02pm to reports of a person on the tracks at the station.
She added: "We sent an incident response officer, a single responder in a car, an ambulance crew and London's air ambulance to the scene.
"We treated one patient for a chest injury. He was taken to hospital as a priority."
On social media people praised the efforts of the unknown rescuer.
Claire Roberts tweeted: "There are some incredible people walking this earth, very brave to take action like he did. He has my greatest respect."
Karen Whitehouse added: "Wow! Brave soul. Respect."