A 22-year-old woman was walking her dog in the park when a man approached her and assaulted her at around 10.30am on Monday, February 1.
It’s believed he made off on foot, possibly towards Wingfield Road, Alfreton.
The victim has worked with police to produce this image of the suspect.
He is Asian, slim, in his 30s and had stubble. He was wearing a black Adidas hooded top.
Anyone with any information should contact DC Adam Gascoigne on 101, quoting crime reference number 5056/16 or call Crimestoppers anonymously on 0800 555 111.