Ben Daly was reported missing on Wednesday (January 26) just before 10pm, Sussex Police confirmed.
Police say he may have travelled to Mitcham in London.
He is described by police as white, 5’8”, of stocky build, bald, with tattoos on his arms in black and grey, and now without a beard. He was wearing a white T-shirt and blue jeans.
Anyone who sees him or who has information about his whereabouts is asked to report it to Sussex Police online or call 01273 470101 and quote serial 753 of 26/01.