Police learned of a serious assault at a Tauranga bar three days after it happened.
Detective senior sergeant Greg Turner said police were first made aware of a serious assault on Tuesday after a young man was hospitalised with a fractured skull.
Mr Turner said the incident was believed tohave occurred in the garden bar area of the Grumpy Mole on The Strand about 2am on December 31.
"A male has been knocked to the ground and assaulted. Obviously we want to speak to anyone who may have been in the Grumpy Mole and witnessed that assault," Mr Turner said.
A Tauranga Hospital spokeswoman said a 47-year-old man from Waihi was admitted at 2.30am and later discharged.