An informal on the tracks at the station at Putney High Street was reported just before yesterday 5 pm (April 21).
The officers and teams of the London ambulance service attended, however, the person was declared dead shortly after.
The incident is not treated as suspicious, and a file will be prepared for the coroner.
National Rail confirmed that all the lines between the thesis stations were closed with delayed services up to 15 minutes.
He had also affected the Southwest Railway Services between London Waterloo and Clapham Junction.
Since then, all services have returned to normal.
If you feel affected by what happened and want to find support, you can communicate with the Samaritans in 116 123 by phone for a confidential chat.
A London Ambulance Service spokesman said: “Yesterday they called us at 4.58 PM (Monday, April 21) for reports from an incident at the Putney railway station, Putney High Street.
“We are a series of resources for the scene, including ambulance equipment, members of our dangerous area response team (heart), a paramedic in a fast response car, an incident response officer and the London air ambulance.
“The first of our teams arrived in three minutes.
“Our teams helped our emergency services partners in the place. Unfortunately, despite the best efforts of the lifeguards, a patient died.”
A British Transport Police spokesman said: “The officers were called to the Putney train station around 5 pm yesterday (Monday, April 21) after the reports of a victim on the tracks.
“They also attended the paramedics, however, unfortunately, a person was declared dead on the scene.
“The incident is not treated as a suspicious, and a file will be prepared for the coroner.”
