A person has died and an ambulance driver was seriously injured in a crash on SH1 at Cambridge.
Police said a vehicle crashed into the back of an ambulance on Tirau Road about 3.39am.
The driver of the vehicle died at the scene.
In a statement, St John ambulance operations deputy chief executive Dan Ohs said two ambulances, two rapid response vehicles, one supervisor, one senior manager and one helicopter responded to the crash.
The ambulance driver is in a critical condition and has been taken to Waikato Hospital.
Another medical staff member inside the vehicle has moderate injuries and has been taken to Waikato Hospital by ambulance.
There were no patients on board.
"Our focus right now is to support our people and our thoughts are with them, their wider family, and friends at this difficult time," Ohs said.
"We are also supporting police with their ongoing investigations into the crash."
The road was closed and diversions were in place.