British Transport Police were called to Yarm station just after 8pm after reports of a casualty on the tracks.
Ambulance and air ambulance crews attended, but the person was sadly pronounced dead at the scene and paramedics were stood down.
It is understood the death is not being treated as suspicious.
A BTP spokesperson confirmed officers had previously been called around 75 minutes earlier to reports of a trespasser on the line, but were unable to find anyone following a search of the area.
The incident is not being treated as suspicious and a file will be prepared for the coroner.”
A North East Ambulance Service spokesperson added: “We were called to an incident at Yarm Railway Station, in Green Lane, at 8.10pm.
“We dispatched two ambulance crews and a duty officer and requested support from Great North Air Ambulance Service.”
