The incident happened on Saturday 29 January 2022 on Kirkstone Road in Starbeck between 7pm and 8pm. A man was seen performing a sex act in a public place.
Officers are asking members of the public to get in touch if they recognise the man in the images below as they believe he will have information that will help the investigation.
The man is described as a white male, aged in his 40s, mousey brown greying hair, glasses, wearing blue jeans and a dark coloured jacket. The man had a small dog with him which had a red bandana around its neck.
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote reference number 12220016755 when passing on information.