Christopher, 62, was last seen on Saturday, October 26, according to Sussex Police.
He is known to frequent Brighton and Hove but could have travelled to Eastbourne, Bognor, Chichester and Littlehampton, the police force said.
“Christopher is 5’ 11”, with very short black hair,” a spokesperson for Sussex Police said.
"He was last seen wearing casual clothing, trainers and a black flat cap, which he usually wears backwards.
"If you have any information please call Sussex Police on 101, quoting serial 739 of 31/10.”
1. Police searching for man, 62, missing from Sussex
Christoper, 62, has been reported missing from Sussex. Photo: Sussex Police Photo: Sussex Police