Authorities suspect the plane is a 19-foot (5.7 metre) aerobatic biplane that was home-assembled from a kit and flown by missing Auckland pilot Daroish Kraidy.
The crew of the San Kawhai was trawling for fish when they brought up a plane in the boat's nets at about 10 a.M., said Trish Sherson, a spokeswoman for fishing company Sanford.
Typically, trawl nets are dragged in a wide arc along the ocean floor to ensnare fish. Buoyancy can make it easier to lift heavy objects in the water than on land.
Kraidy's Acro Sport plane is the only plane listed as missing by New Zealand's Civil Aviation Authority. Authority spokesman Mike Richards said the Acro is relatively lightweight and is made from aluminum and wood, with fabric wings.
More From This Section
Kraidy, 53, took off March 25 from Ardmore airfield near Auckland. Minutes later, his plane disappeared from radar screens, leading authorities to conclude he either switched off the plane's transponder or was flying at a very low altitude.
His ex-wife noted some similarities to the disappearance 17 days earlier of Malaysia Airlines Flight 370, with 239 passengers on board. That plane has not been found.
Police said today that fishermen were transporting the wreckage to a bay near Great Barrier Island, about 90 kilometers (56 miles) northeast of Auckland.
Police said they were heading to the scene and would use a barge that could lift the plane aboard and transport it back to Auckland. They said they were contacting Kraidy's family and friends about the discovery.