Police were at the scene of a serious crash on State Highway 30, Horohoro where one person is said to be critically injured.
Emergency services were alerted to a car that had rolled at the intersection of State Highway 30 and Apirana Rd at about 10.40am, police said in a statement.
"One person is said to be critically injured. Another person has minor injuries."
A St John spokeswoman confirmed one person had minor injuries and was treated at the scene.
The other person was flown to Waikato Hospital in a critical condition.