A man shouted at a woman as she walked past him before exposing himself.
The incident happened between 8.30am and 9am on Wednesday, February 20, in Thornton Park, Kingsthorpe, when a woman was walking through the park and saw a man standing near trees and exposing himself.
The man called out to the woman, who ignored him and continued on her way.
The man is described as white, in his mid 20s to early 30s, about 5ft 11in to 6ft, with a medium build. He had an olive complexion and black stubble, and was wearing a hooded khaki coat, dark coloured trousers and a dark coloured, woollen beanie hat.
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101. Alternatively, they can call Crimestoppers anonymously on 0800 555111.