The light plane, flown by off-duty Qantas pilot Paul Whyte, took off from Lismore on the afternoon of March 21 and disappeared from the radar about 11 kilometres north-east of Byron Bay.

Mr Whyte had frequently piloted the Cessna 172 single-engine aircraft, flying a regular route east to the coast before looping back to the Northern Rivers Aero Club.

The seemingly routine flight went over the water before it crashed into the ocean at nearly 200km/h.

An initial search using planes, boats and sonar was was unable to locate it, so the Navy was called for assistance.

HMAS Gascoyne, a minesweeper, started searching the area where the plane disappeared on on Thursday night and located the wreckage at 12.40am on Friday morning, in water around 73 metres deep.

It had broken into at least three pieces. The body of Mr Whyte, 46, was not found.

Footage released by the Navy showed pieces of the plane's blue and white fuselage crumpled on the ocean floor, with the registration number was clearly visible, as fish darted around the wreckage.

A short distance away was a wheel which appeared to be from the plane's landing gear.

Mr Whyte worked as a first officer for Qantas but was flying solo in a personal capacity at the time of the crash.

Police do not think they will salvage the wreckage and say the circumstances of the crash are not suspicious.

With Megan Levy