Mr Urlich and Ms Raharuhi always knew the dunes were urupa (burial grounds])
Dr Robinson says people shouldn't be surprised that koiwi will be found occasionally, particularly where weather, erosion and even earthworks can uncover bones that have lain undisturbed for centuries.
He had exhumed koiwi on about 10 occasions during the last three years, and said there were some basic steps to follow for those who came across what might be human remains.
"It's really helpful if people can tell us where the remains were found," he said. "It is useful if they are able to take a picture of what they've found — using a phone camera is absolutely fine. If people can also take a photo of the general environment where the bones have been found, that can be very helpful, because it gives us a broader context, and assists with identifying their exact location, especially when there is very little diagnostic material left.
"If bones are found eroding out of the ground, the best thing is to leave them alone, or perhaps cover them with sand or soil if that's practical, then mark the spot so they can be followed up later. If bones are found lying on the beach, where they might be affected by the tide, people can take them to the grassy area above the high tide zone, cover them with something like a tarp or rug and mark the spot where they have been placed."
They should then call the police or Heritage New Zealand, who would then contact the local iwi and hapū.
"There are a number of indicators that tell us if bones are older. These include factors like wear on teeth from eating fern root, the manner of burial, in some cases, and evidence like the distinctive 'rocker jaw' that is a feature of Māori bone structure.
"These and other clues will show whether we're dealing with a historic situation or a potential crime scene.
"Heritage New Zealand has processes in place that ensure the human remains are managed sensitively.
"Their cultural origins are not important. The key thing is that they are treated with respect, and that iwi are involved and correct tikanga is followed as appropriate.
"As a general guiding principle, I treat koiwi with the same care and respect that I would treat my own grandparents.
"If people follow these simple guidelines, koiwi can be laid to rest with care and respect."