Heritage New Zealand denies claims human bones have been found on land cultivated for new avocado orchards in the Far North.
Conservationists and an iwi source told RNZ bones were uncovered by contractors at Motutangi, but not reported to the authorities.
Heritage New Zealand's area manager, Bill Edwards, said the archaeologists found animal bones but no human ones.
But he said they did discover Māori artefacts including a greenstone adze, and that was significant.
"It's about 100 millimetres long by about 40 millimetres wide and it's what we call a type 2B which is basically the Swiss army knife of adzes, they were a great all purpose tool."
Other items to be found included a small stone sinker and a wooden fern root pounder or patu aruhe which was preserved because it was found in a swampy area.
Wooden artefacts were rare in archaeological sites and were only preserved in either very wet or very dry areas, Mr Edwards said.
The pounamu was from the South Island's West Coast, which raised questions about the extent of trade going on at the time, he said.
"It's travelled a long way and you've got to wonder about the trade mechanisms that were happening in order to trade that stone that came from the West Coast all the way up to the Far North."
The diggers at Motutangi also turned up another rare find: a wooden fern-root pounder, preserved for centuries in the swampy ground, Mr Edwards said.