A 21-year-old woman boarded the route 418 bus in Kingston heading towards Epsom on May 7 at 4.40pm.
She sat down in the row of seats behind the exit doors by a window. A short time after sitting down, a man boarded the bus and asked to sit next to the victim, which she allowed.
However, the man then put his hand on her and started touching her leg inappropriately. This prompted the victim to tell the suspect to stop touching her before she quickly stood up and moved to another seat.
Another passenger informed the bus driver of the incident and the man was removed from the bus.
Detective Chief Inspector Michael Dougall said: “If you recognise this man or have any information about his whereabouts, please contact police right away. It is vital we identify him. No piece of information is insignificant and could help us in our investigation.”
Anyone who can identify him is asked to tweet @MetCC or call 101 referencing CAD 1209/17AUG. To remain 100% anonymous, contact the independent charity Crimestoppers on 0800 555 111.