A post mortem examination would be carried out to determine the exact cause of death.
Inspector Johnson said the alley and the area where the man was found have been cordoned off for a scene examination and police were speaking with a number of people who were in the area when the altercation happened.
He expected enquiries to continue throughout the day.
Mr Millanta was described at the time 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 and 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.