At a media conference, Detective Inspector Karl Thornton of the Waikato CIB said a scene examination was under way as investigators piece together what had happened.
"Initial indications are a couple staying in a caravan outside 25 Beach Rd heard a disturbance about 1am and went to investigate," Mr Thornton said.
"They have encountered a man and told him to leave but then the husband [was stabbed]."
Mr Thornton said there were a lot of people out in the area celebrating at the time and it was these people who may hold the key to identifying the offender.
"We would like to speak to anyone who saw or heard anything suspicious or who may know the identity of the attacker," he said.
Clodagh Kendal, who lives three doors down from the property where the attack occurred, said detectives searched the grounds of neighbouring properties yesterday morning, looking for a possible weapon.
The attack had disturbed the small community, she said.
"It's a quiet resort here, it's a family place and we're not used to this sort of thing happening. There's too much drinking and drugs in our community these-days," Ms Kendal said.
Local resident and television personality Bill Ward said a man who lived across the road from where the attack occurred heard a scream and was the first person to respond.
"Bryan grabbed his medical kit out of his truck and patted the side of [the victim's] head and he said it [the blood] was flowing really quickly," Mr Ward said.
The occupants of the property were well known in the community but Mr Ward didn't know what their relationship to the victim was.
Meanwhile, Tauranga police were looking to speak with the victim of an unprovoked vicious stomping which took place about 11.30pm New Year's Eve on Marine Parade, between Banks Avenue and Grove Avenue.
Detective Kevin Shields said witnesses saw a man stomping on the head of the victim numerous times.
"A police foot patrol was moving through the crowd to intervene. The offender ran across the road, to the Main Mount Beach where he was located and arrested," Mr Shields said.
After the attack the victim was seen staggering through the crowd towards Banks Ave. "He was heavily bleeding and may have lost a couple of teeth in the attack," Mr Shields said.
"We'd like the victim to contact us so the appropriate support can be offered."
Police also wish to speak to anyone who witnessed the assault.
Western Bay police arrested 97 people in the three days leading up to, and including, New Year's Eve.
CAN YOU HELP?
Waihi Beach attack
Call Acting Detective Senior Ross Patterson at Waihi Police Station on (07) 863 8179.
Mount Maunganui assault
Call Detective Kevin Shields at Tauranga Police Station on (07) 577 4300
Alternatively, call Crimestoppers on 0800 555 111 to report information anonymously.