A person has died in a serious crash between a car and milk tanker in Northland early this morning.
Emergency services were called to State Highway 1 near Brynderwyn Hill, Northland, just before 2am.
St John said another person was taken to Northland Base Hospital in a moderate condition.
State Highway 1 is closed between Kaiwaka-Mangawhai Rd and Mangawhai Rd as a result of the crash.
Police said just after 6.30am that the road remains closed as officers and emergency staff work at the scene still.
Northbound traffic is being diverted via Mangawhai Rd, Tomarata Rd, Insley St, Moir St, Kaiwaka Mangawhai Rd and then back on to SH1.
Motorists heading southbound are being re-directed along the same route, in reverse.
NZ Transport authorities are also warning heavy vehicles in the area that the Tomarata Bridge in Mangawhai may not be suitable for them to use.
People are being warned to avoid the area or expect delays this morning.