Police are appealing for witnesses and information following reports a man exposed himself to a woman in Berkhamsted on August 1.
It happened at around 8.30am in woods off New Road.
Officers went to the scene and a 35 year old man was arrested in connection with the incident.
There were dog walkers in the area at the time and officers are keen to speak with them to see if they saw what happened.
If you have any information about the incident or any other information which would assist the investigation, please call 101.
Alternatively you can contact Crimestoppers anonymously on 0800 555 111 or visit their website crimestoppers-uk.org.