BTP officers were called to Riddlesdown rail station in Purley on Friday, 22 March after a report that a woman and a child had been struck by a train.
The incident was reported to BTP at 8.29am and was also attended by Metropolitan Police officers.
Medics from the London Ambulance Service also attended, but a woman and a child were declared dead at the scene.
The station has been temporarily closed while officers and medics deal with the incident.
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