"An investigation is now underway to establish the circumstances which have led to this man being found unconscious," he said.
"It's too early to speculate on what has occurred or whether any weapons have been involved.''
Inspector Johnson said the alley and the area where the man was found have been cordoned off for further examination.
The victim was described as a Maori man wearing a blue and beige checked shirt with a white t-shirt underneath, blue jeans, light brown boots and a black woollen hat.
Police would like to hear from anyone who was at the Retro Bar early this morning and who witnessed a fight in the car park outside the bar.
They would also like to hear from anyone who saw the man unconscious near the back of KFC about 3am.