British Transport Police, along with Sussex Police, were called to the station at 8.15am, where the body of a man was discovered.
The train involved was the 8.03am Brighton to Portsmouth Harbour Southern service, and the line was shut for three hours.
Replacement bus services were in place between Brighton and Littlehampton.
Ambulance and fire servies were also in attendance.
A BTP spokesman said: “This incident is currently being treated as non-suspicious and anyone with any information is asked to contact British Transport Police on 0800 405040.
“A file will be prepared for the Coroner.”
For the full story, see the Shoreham Herald, out Thursday, May 30.