A man is fighting for his life in Auckland Hospital after he was attacked in a North Shore toilet block last night.
Senior Sergeant Grant Tetzlaff said the man was found in the toilet block on Lake Road, Belmont, about 8.30pm.
He was taken to Auckland Hospital by ambulance in a critical condition.
A scene examination is taking place today to determine what has happened to the man.
It is not yet known whether a weapon was used in the attack.
"By this time tomorrow we should have a better idea of what has occurred."
Mr Tetzlaff said police are yet to speak to the victim.
"He's having some surgery either this evening or late this afternoon and he's in a medically induced coma at Auckland Hospital."
Mr Tetzlaff said police spoke to a number of witnesses last night and are interested to speak to anyone who was in the area around 8pm.
Anyone with information about the attack should contact North Shore Police on 09 488 6200 or Crimestoppers anonymously on 0800 555 111.