Police are investigating a report of a 14-year-old girl being approached and touched by a man near Rickmansworth Aquadrome.
The man touched the girl on the arm and neck before he appeared to be disturbed by a member of the public driving past shortly before 5pm on Thursday, March 28.
The man then made off from the area. The girl was uninjured and officers are following a number of lines of enquiry regarding the incident.
Three Rivers chief inspector Nick Lillitou, said: “I understand this will have caused alarm to the public and I would like to reassure you that we are doing all we can to trace the offender and have increased patrols in the area and around local schools.
“If you saw what happened, or have information about the incident, please call the non-emergency number 101 quoting crime reference 41/28635/19 or anonymously report through Crimestoppers at www.crimestoppers-uk.org”.
“We would be particularly keen to trace the person who drove past, so if this was you please do get in touch.”