Bogus St Barnabas House charity collector in Shoreham
The man was in Tarragon Way, in Shoreham, at around 7.35pm but ran off when he was asked for identification.
He is described as white, in his early twenties, wearing dark trousers, a dark jacket and a flat cap.
He was carrying a St Barnabas collection bucket.
A Sussex Police spokesman reminded residents to always check for identification.
Anyone with information, or who sees him again, can call 101 quoting reference 1455 of 20/3.