The Civil Aviation Authority had been notified and was arriving tomorrowto start its own investigation.
After the CAA inspection was completed the wreckage would be removed.
It is the second fatal air crash in Northland inside two months.
On November 16, Russell resident Ricco Legler, 72, died when his glider crashed near Kaikohe.
The alarm was raised late in the afternoon when Mr Legler, a highly experienced pilot, failed to return to Kaikohe aerodrome after a solo flight.
The wreckage was found about 3km northwest of the aerodrome later that evening.
Coincidentally, a third but not fatal plane crash occurred last April on another dairy farm only14km north of where yesterday's tragedy occurred.
In that incident, a man and woman walked away with minor injuries after crash landing in a paddock on Pouto Rd, south of Dargaville, after their two-seater Zenair plane developed engine trouble.
The pilot had made a perfect emergency landing on a flat paddock, the most serious damage done when the plane crashed through a fence before stopping.
Had the pilot carried on flying another 100 metres or so he would have hit a hillside.