Police are searching for a man accused of sexual assault in the Bailgate area of Lincoln.
Officers released a CCTV image of a man they want to speak to as part of enquiries.
The female victim was reportedly walking a dog by herself just after 7am on Thursday, December 27 when a male placed his hand on her right buttock before walking on.
The incident happened between Greggs and the Duke William Hotel.
Anyone who recognises the person pictured or has any information is being asked to call 101 quoting incident number 86 of December 27.