The incident on the tracks means that all lines between London Waterloo and Clapham Junction were closed, and major disruption is expected until the end of the day.
Lines have now reopened, but Network Rail are warning that trains still face being cancelled, delayed by up to 90 minutes or revised.
The incident means that services to other stations beyond Clapham Junction such as Wimbledon and Richmond have also faced major disruption.
A British Transport Police spokesperson said: “We were called to Queenstown Road railway station at 11.49am on 9 April to reports of a casualty on the tracks.
“Paramedics also attended and sadly a person was pronounced dead at the scene. This incident is not being treated as suspicious, and a file will be prepared for the coroner.”
:: If you are experiencing feelings of distress, or are struggling to cope, you can speak to the Samaritans, in confidence, on 116 123, email [email protected], or visit the Samaritans website to find details of your nearest branch.
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Live updates
Delays on the A10
Traffic is slow on approach to the works with southbound traffic queues back Lordship Lane, northbound traffic queues back beyond Stamford Hill Broadway and westbound traffic queues back beyond Tottenham Hale.
Delays on the A13
Westbound traffic is experiencing significant delays, with queues building back towards Marsh Way.
Eastbound traffic is also slow past the scene at Castle Green, with congestion stretching towards Prince Regents Lane due to onlookers.
Further delays are likely along diversion routes including Renwick Road, Ripple Road and through Dagenham.
DLR line part closed
There is currently no service between Bank / Tower Gateway and Poplar / West India Quay on the DLR.
Please use the Jubilee Line, Elizabeth Line and local London bus services. Allow extra time for your journey.
Minor delays on the Central line
There are minor delays on the Central line due to train cancellations.
Piccadilly line update
Piccadilly line facing minor delays between Rayners Lane and Uxbridge after earlier fault.
Minor delays on diversion routes around Romford
Traffic is moving along diversion routes via Ardleigh Green Road and Gubbins Lane, although delays of around three to five minutes are being reported.
Similar delays are affecting Gooshays Drive and North Street heading away from Romford.
Metropolitan line resumes good service
The Metropolitan line is providing a good service.
Piccadilly line update
Piccadilly line hit by severe delays between Rayners Lane and Uxbridge after points failure.
Delays on London Road and Waldram Park Road with queues building
Traffic is slow on approach, with eastbound delays on London Road back to Waldenshaw Road and westbound queues on Waldram Park Road stretching to Stanstead Road.
Motorists should expect delays.
A10 delays
Drivers are advised to approach with caution as traffic is slow near the works.
Southbound queues stretch beyond Lordship Lane, northbound traffic is backed up to Seven Sisters Road, and westbound delays extend past Tottenham Marshes.