At 3.25pm on Thursday, 3 June, a 16-year-old girl was sat at a picnic bench in a wooded area behind The Folly pub in Charlton Road when she was approached by an unknown man.
He started talking to her and then made sexual comments toward the victim, at which point she left and told her parents, who reported the incident to the police.
The girl has been left shaken and distressed by this incident.
The man is described as white, of skinny build, in his late 20s to early 30s and 5ft 10ins to 6ft tall, and spoke with a local accent.
He was wearing a blue baseball cap, a black facemask and was carrying a CEX drawstring carrier bag.
Police are appealing for anyone who may have been in the area at the time, or used the public footpath which runs behind The Folly.
If you have information that can help officers with their enquiries, contact us online or via 101, quoting 44210216366.