A man has died after being hit by a train at Queenstown Road station.
A spokeswoman for British Transport Police confirmed that they were called to reports of a man struck by a train just after 3pm this afternoon.
Police and paramedics attended but the man, who has not yet been identified, died at the scene.
The incident is not being treated as suspicious and officers are working to inform the man's next of kin.
All lines are blocked while emergency services deal with the incident and no trains are running between Clapham Junction and London Waterloo.
Jon Lucas, from Richmond, was on the train involved in the incident and said that staff and passengers remained calm.
He told the Wandsworth Guardian: "We'd left Vauxhall and about to arrive at Queenstown Road when the train halted.
"The first three carriages were on the station, the rest of the train was not.
"The guard came over the tannoy that the train had been involved in an incident, then five minutes later we were asked if anyone wanted to get off at Queenstown Road.
"On emerging from the station the emergency services were already there and more were on their way.
"People were calm and so was the guard."
On a train stopped just outside Queenstown Road - all trains around stopped pic.twitter.com/Q9YipSEFan— Fay Watson (@FayAnnaWatson) April 24, 2017
Trains may be delayed by up to 60 minutes, cancelled or revised.
The disruption is expected to continue until the end of service.
Passengers can use tickets on Southern rail, Great Western Railway, London Underground and London Buses on reasonable routes.
More to follow.