The reported offence happened at around 5.30am on Friday morning.
The victim was assaulted near to the McDonald's restaurant in the Old Market area of Halifax, police said in an appeal.
Officers are asking members of the public for help to identify the man pictured.
He is described as a white male in his late teens or early 20s.
Detective Inspector Gary Stephenson, of Halifax CID, said: “I would like to ask the public for help with establishing the identity of this man, as he may be able to help assist us with our enquiries.
“If anyone was in the area that morning and witnessed anything or saw anything suspicious, we would like to hear from you.”
Anyone with any information is asked to call 101 or information can be passed to Crimestoppers anonymously on 0800 555 111.