Myth and mystery: Who were the first Europeans to visit New Zealand?

Just when did the first contact between Maori and European take place? The history books only go back to the sighting of New Zealand by Abel Tasman and landings by James Cook, but a careful, detailed study of Maori oral history and the many shipwrecks around New Zealand's coast indicate contact may not only have been much earlier than European history suggests, but may have happened on several occasions.