First to fly?

When I was in New Zealand recently I visited a very interesting air museum in the South Island where Tiger Moths and other old de-Havilland aicraft were being renovated back to flying condition. While there I got talking to one of the craftsman who told me that a New Zealand aviator was the first to acheive powered flight, but it was never recognised by the Americans on some obscure technicality. Does anyone know anything about this?