Police are appealing for witnesses after a man was found unconscious near Bognor pier.
In a statement it said the 23-year-old from Portsmouth was found laying in the pavement on the seafront between the pier and Waterloo Square by passers-by.
The man was taken to St Richards Hospital, Chichester, where it was established that he had suffered head injuries including a bleed on the brain, it confirmed.
It added that the man remains in hospital, but is now conscious and his condition is not assessed as life-threatening.
Detective constable David Midgley said: “We would like to hear from anyone who was out and about along the seafront during the early hours of that Sunday morning (May 6) and who saw anything suspicious or saw the injured man.
“At this time we have not established the full circumstances around this incident but we are carrying out a thorough investigation and are keeping an open mind.”
Anyone who can help is asked to call 101, quoting serial 1146 of 07/05.