A woman was touched inappropriately while walking close to Wicksteed Park in Kettering.
The incident happened close to the entrance in Barton Road.
The victim walked past a man, standing next to a car, who asked her if she wanted a lift.
She declined and he then made an inappropriate suggestion.
As the victim walked away the man touched her inappropriately.
The offender was about 5ft 8in, in his 20s and slim.
He had black hair slicked back with gel, a local accent and possibly a moustache.
The car he was driving was quite old and could have been green.
The incident happened at about 6.15pm on Friday, February 26.
Police would like to speak to anyone who may have witnessed this incident or who may have any information regarding it.
Witnesses or anyone with information about this incident can contact police on 101 or Crimestoppers anonymously on 0800 555 111.