Police have released a comfit image of a man they would like to speak to in relation to the assault of a 68- year-old man in Darwin City early Saturday morning.

The man is described as Caucasian appearance, aged in his mid-20s, approximately 180cm in height, muscular build clean shaven, dark short hair, wearing a white t-shirt.

Police urge anyone who may recognise this man or anyone who may have witnessed this incident to contact Police on 131 444 or Crime Stoppers on 1800 333 000.