Police confirmed two people had now died.
"Sadly, the two people died at the scene.
"Brigham Creek Rd remains closed and diversions are in place at State Highway 16 and near Joseph McDonald Drive.
"The road is expected to be closed for some time while the Serious Crash Unit is in attendance."
Officers were called to the area just after lunchtime.
Road authorities say a section of Brigham Creek Rd will soon be closed between State Highway 16 and Joseph McDonald Drive as emergency services work at the scene.
"Please follow the directions of emergency services and expect delays," an alert from Waka Kotahi NZ Transport Agency said.
Motorists are asked to delay travel or find an alternative route.
More soon