A boy climbed aboard a bus and racially abused the driver for refusing to accept his ticket.
The Stagecoach bus driver was in Endwell Road, Bexhill, when a boy and a girl boarded the bus and tried to use tickets that were not valid at about 5.55pm on Friday 18 July.
When the driver told them so he was racially abused by the boy before both children got off the bus and left.
Inspector Lee Lyons said: "We have been trying to identify the boy in the CCTV so we can speak to him but have not had any luck so far.
"A number of passengers were on the bus and would have heard the racist abuse and we are hoping some of them could come forward to tell us what they saw and heard.
"Although this happened a few weeks ago, it is such a striking incident that I still believe those who were there will remember it."
Anyone with information should email email@example.com, call 101 or contact the independent charity Crimestoppers anonymously on 0800 555111.