The human remains that stopped work on the Huntly section of the Waikato Expressway late last month was that of a young male.
Once excavated, the remains, which appeared to have been buried in a kumara pit, were sent to Auckland for analysis.
NZ Transport Agency's Hamilton highways manager Kaye Clark said archaeologists had found that the koiwi was aged between 17 and 20 and was reasonably healthy apart from abnormalities in the lower spine and having extremely worn teeth for a person of that age.
"At this point we have not been given a specific date or time period to how long this koiwi has been buried but material from the site has being sent for carbon dating," said Mrs Clark.
The koiwi was reinterred at Taupiri on April 5.
Work stopped at the site of the koiwi discovery for five days, resuming on April 4. Work did not stop on other parts of the project following the find.
Archaeologist Collin Sutherland said it was "one in a thousand" to find remains in a kumara storage pit.
"It's fairly rare to find human remains in a kumara pit but it's not unheard of. Most often you get the reaction that it's counterintuitive to have the dead associated with food," said Mr Sutherland.
The kaitiaki, or guardian, of the site Kawe Nikora said her main purpose on the site was to protect the environment.
"We look after the fish and the birds and especially the bones that are found. We try and protect them and relocate them away from the Expressway.
"Is our job important? Yes it is when you think of the history and the Maori Wars. The second king said 'once the land was taken, it should be returned'. What we are saying here is that what happened in the past has happened but we are now here to make sure no more damage is done to the area and everything is safe."
She said if they found one set of remains there would be others around.
"We will continue here throughout the whole project... I need people to know the importance of having a kaitiaki ... It's really important that we protect our land."
Mrs Clark said project protocols which NZTA had developed alongside Waikato-Tainui immediately came into play when the remains were uncovered.
"Our protocols include provisions for kaitiaki to work on site, as needed, to monitor earthworks as they unfold. This discovery was made by the kaitiaki and the project archaeologists working alongside each other, which is exactly what should happen," she said.