Train services across News Shopper's patch are experiencing severe delays after a person was hit by a train at Denmark Hill.
Services affected include those between Sevenoaks and Blackfriars, and between Datford and London Victoria.
All lines have now been reopened, but trains may still be delayed by up to half an hour or cancelled at short notice.
The issue has been compounded by signalling problems at London Cannon Street, meaning fewer trains are able to run on all lines from this station.
Disruptions are expected to last into the evening.
Tickets are being accepted on First Capital Connect, London buses and London Underground services.
A British Transport Police (BTP) spokesman said: "BTP officers were called to the line near to Denmark Hill London Overground station, on Thursday, June 12, following a report of a man’s body on the tracks.
"Officers from BTP and the Metropolitan Police Service attended the incident, which was reported to BTP at 2.01pm and is currently being treated as non-suspicious.
"Paramedics from the London Ambulance Service also attended but the man was pronounced dead at the scene.
"Enquiries into the man’s identity and how he came to be on the tracks are ongoing.
"A file will be prepared for the coroner."