The news came at 2.15pm today and was announced by the firm with ‘great sadness’.
Taking to Twitter, the company said: ‘It is with great sadness that we report a person has been hit by a train between Barnham and Chichester. All lines are blocked between these stations whilst the emergency services work to deal with this incident.
‘At present, no trains are able to run between Barnham & Chichester.
‘If you are looking to travel between these stations or along this route, please allow extra time as you may need to use an alternative route this afternoon.
‘Rail replacement buses have been requested to run from Bognor Regis, Barnham, Chichester and Havant.
‘Once these are confirmed, we will provide an update.
‘If you are travelling between Barnham/Chichester/Havant, you will need to use an alternative route this afternoon.
‘Please delay travel until later today where possible.’
A later update said trains can run to Bognor Regis but on a reduced service.
The following services will run ‘where possible,’ the operator said. Between Brighton and Littlehampton/Barnham, between Horsham and Barnham/Bognor Regis between Chichester and Havant.