Construction workers at the site of the country’s largest retail store have unearthed a significant cache of swamp kauri.

While carbon-dating has yet to be carried out, swamp kauri are prehistoric kauri trees which can be buried for 800 to 50,000 years under peat swamps in the North Island - predating the last Ice Age.

At one time New Zealand swamp kauri was valued at over $10,000 per cubic metre, making it one of the most expensive timbers in the world.

Traditional carvers and students at Te Wananga o Aotearoa Mangere, a Maori learning environment in South Auckland, are set to benefit from the find as the recipients of a donation of the ancient taonga - which will be carved by Tohunga Whakairo (expert wood carver) Troy Hart-Webber into pou whenua.

Nido managing director Vinod Kumar says the find at the Henderson construction site was immediately recognised by one of the workers overseeing the excavation of the foundations of the new 27,000sqm furniture, furnishing and homeware store.

“Our assistant site manager Lisa Wade (of iwi Ko Kahungunu kia Heretaunga me Rongowhakaata me Te Aitanga A Mahaki toku iwi descent) identified the significance of the find straight away.

“We thrilled to be able to return this ancient taonga to local Maori, the local wananga and their tohunga whakairo,” he says.

Lisa Wade says the trees appear to have been blown over in a storm and were facing the same direction - which has cultural significance.

“Tane Mahuta - the Maori god of forests and of birds was said to be made of kauri making this taonga is particularly precious to the Maori people,” she says.

Kumar says the centuries old wood was discovered at a depth of four metres and has been anaerobically sealed in a chemically balanced environment that has kept the timber preserved in exceptional condition.

More than 20 pieces of swamp kauri which measure up to seven metres in length and 90cm in diameter, were was recently blessed in a karakia ceremony, and will be excavated and loaded onto a truck for transport to the recipients in Mangere this afternoon.

Construction on the more than 31,000 square metre site at 158 Central Park Dr, Henderson began in October 2018 and is expected to be completed around spring of this year.