Pat West of Glacier Southern Lakes Helicopters said another pilot, Brendan Hiatt, made the discovery Wednesday, the Otago Times reported. Hiatt, who had passengers on board, hovered low enough to identify a tail section.
"He was on his way back from Milford Sound on a commercial job and spotted something out of place," West said.
The crash in January 2004 in a remote mountainous area in the South Island killed Campbell Montgomerie, 27, of Waikato and his girlfriend, Hannah Timings, 28. Timings was on an extended visit to New Zealand from England.
Ground and air searches in 2004 failed to find the helicopter. Investigators say it may have been hidden under snow for some time since then, while West said it was a green color that did not show up well against vegetation.
Timings was a project manager in London for the furniture business owned by David Armstrong-Jones, Viscount Linley, son of the late Princess Margaret, The Daily Telegraph of London reported.
Police in New Zealand said the families of both Montgomerie and Timings had been told of the discovery. DNA testing will be required for formal identification of their remains.