Police are investigating a collision between a car and a cyclist which occurred shortly before 6.30am on Thursday (1 August) on the A259 Hawthorn Road at Wick, Littlehampton.
It happened as both were travelling east. Sadly the cyclist sustained fatal injuries.
The car involved drove away but was later traced.
The A259 eastbound was closed to traffic while the incident was being dealt with and police would like to thank motorists for their patience and understanding.
A man has been arrested on suspicion of failing to stop and causing death by dangerous driving. He is currently in police custody.
Anyone who saw what happened, in particular, those who may have dash-cam footage, is asked to report details online, by email to firstname.lastname@example.org or by phone on 101, quoting Operation Glenview.