You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
Three single-occupant vehicles were involved in the collision at Lovells Flat, near the SH1 intersection with Hall Rd, about 12.45pm.
St John spokesman Gerard Campbell said one person with critical injuries was airlifted to Dunedin Hospital while two more with moderate injuries were taken by ambulance.
Emergency staff transferred a heavily bandaged patient to one of the helicopters about 2.20pm, after which both helicopters departed.
However, Senior Sergeant Jim Jordan, of Milton, said it was too early to draw conclusions about the cause of the crash.
He said the Serious Crash Unit was reviewing the incident, and would publish its findings at a later date.
"We’ve had an incident where three single-occupant vehicles have collided on a bend in a passing lane, leading to injuries for all three drivers.
"Other than that, there’s nothing else I can add at this stage while matters remain under investigation."
SH1 was still closed at 2.45pm, but a single lane had reopened for light traffic by 4pm.