An Australian holiday maker who was stabbed at a New Zealand beach resort on New Year's Day has died.
Robert Murray Wilkinson, a 64-year-old New Zealand expat from Queensland, died in Waikato Hospital on Thursday.
"What was an investigation into a stabbing is now a homicide investigation," Detective Inspector Chris Page said.
Police said Mr Wilkinson and his wife told a man to leave after hearing a disturbance outside their caravan about 1am on Tuesday.
They were staying in a caravan in front of a friend's house.
"The tragedy that has befallen Mr Wilkinson's family is one felt by the greater Waihi Beach and Waikato communities and we ask anyone with any information to contact us," Det Insp Page said.
Eastern Waikato Area Commander Inspector Dana McDonald earlier asked hundreds of New Year revellers in the area who may have taken pictures to help investigators.
"People often take snaps of New Year's Eve revellers and then think nothing more of them. What we are after is images of people in and around Beach, Hinemoa and Ocean View Roads, the surf club, camping ground and Esplanade between 12.30am and 1.30am," Insp McDonald said.
A post-mortem examination will be conducted in Auckland on Friday. A forensic examination of the scene is continuing and police officers have been searching for the weapon and speaking to people in the area.
The investigation was being made more challenging by the transient nature of the population, which swells from 3000 to about 16,000 during the holiday period.