The male was walking along an alleyway in Richmond Avenue when he was attacked from behind. Three men stole his wallet which contained cash and bank cards. The attack took place between 7.30pm and 7.45pm on April 30.

DC Jo French, of Arun CID at Bognor police station, said: "As a result of this attack, the victim suffered a minor injury to his face and required hospital treatment due to feeling unwell as he was suffering from mild concussion.

"Richmond Avenue is the first road to the north of the busy Aldwick Road.

"I would urge everyone to think back to that evening and contact me if you saw any part of this incident or have any information as to the identities of the attackers.

"Please help us to bring them to justice for this despicable and violent crime."

The robbers are described as:

suspect one - white, slim build, 19/20 years, brown short hair with a long fringe and piercing eyes, wearing a blue top with a white collared T-shirt underneath, faded blue jeans and white trainers;

suspect two - black Caribbean, large muscular build, mid-20s, very tight curled black hair, an old scar about three inches long behind his right ear and wearing a white round-necked T-shirt; and
suspect three - white, slim build, 5ft 9in tall, wearing a blue jumper, jeans and trainers.

Information to DC French on 0845 60 70 999.