A casualty on the tracks between Wimbledon and Sutton was reported just before 8pm yesterday (November 17).
Officers and London Ambulance Service crews attended, however, the person was pronounced dead shortly after.
The incident is not thought to be suspicious and a file will be prepared for the coroner.
All lines between Wimbledon and Sutton were closed as the incident was dealt with.
The incident caused major disruption, however, services returned to normal just after 12am.
If you need someone to talk to, Samaritans are available to contact any time day or night on 116 123.
A spokesperson for British Transport Police said: “Officers were called to a report of a casualty on the tracks just before 8pm last night (17 November) near Sutton Common station.
“Officers and paramedics attended and sadly a person was pronounced deceased.
“The incident is not thought to be suspicious and a file will be prepared for the coroner.”
