"The other vehicle has come out of an intersection at Old Taupo Rd," he told the Herald. "They wouldn't have seen each other to begin with, then it appears the rental car has crossed over, less than 100m from the intersection."
The couple picked up their rental car in Auckland.
A mother and daughter were on their way home in the Land Cruiser, which ended up halfway up a bank off the road.
The pair were uninjured but badly shaken, he said.
Alcohol and speed were not believed to be factors, Mr Hamilton said.
Waotu South Rd resident Sharon Edwards knew the intersection of Old Taupo Rd and Waotu Rd very well and said locals knew to treat it with caution because of its unusual layout.
"It's quite dangerous if you're not watching what you're doing. You come around a corner and you've got one road going straight through and one to town. And if you're not watching you can run into someone."
She hadn't heard of any crashes happening in that particular spot before.
"There probably have been but I haven't heard of any."
The Taupo Police Serious Crash Unit is investigating the crash and whether fatigue and distraction were factors.
The crash occurred on a rural 100km/h stretch of road that was not a typical spot for crashes in the region, Mr Hamilton said.
Senior Sergeant Chris Turnbull said they were experiencing delays in releasing the woman's name because of the difficulty of contacting next of kin overseas.
