An investigation was launched after a 46-year-old man was seriously assaulted on Frederick Street.
The incident occurred around 1.25am on Wednesday, February 2 and officers have released an image of a man whom they believe can assist them with their enquiries.
He is described as white, of medium build, with short dark hair, and aged in his mid-twenties.
He is shown in the image wearing a light blue hooded sweatshirt with a logo.
Detective Constable Melissa Silva said: “I am asking that the man pictured makes contact with the police in order that further enquiries can be conducted.
"I am also asking that if any member of the public recognises the man that they make contact with the police.”
Anyone with information should call contact 101 and quote incident 0161 of 2 February, 2022.