A toki (adze) has been discovered on the ground surface at Marycrest, in Te Horo, during work on the Peka Peka to Otaki Expressway.
The exciting discovery was found by Oriwa Carkeek a member of the Project Kaitiaki team.
Toki were an everyday tool used for cutting, digging and woodworking, as well as ceremonial purposes.
"This particular one is most likely made from argillite, which was traded from the Nelson and Durville Island area where it was quarried," Opus archaeologist Emily Cunliffe said.
"Argillite was prized for making adzes as it flakes really well and is a very strong stone.
"I'm not sure of the date of this item as they were made throughout Maori history, but hopefully when we do radiocarbon dating on some of the Marycrest sites we may be able to get an idea of the time period this relates to."
The discovery has come just in time for the archaeological open day this weekend, however this particular toki will not be on display.
The toki has been sent away for archaeological analysis and a report will be completed on it.
Archaeological analysis includes "identifying the type of stone, where it might have come from and studying the site where it was found for anything else it might tell us.
"For example if there is charcoal in the same area we can carbon date that for an approximate age and so on.
"This one has been chipped on the blade (top end), which may have been why it was discarded."
While the newly discovered toki will not be present, archaeologist Emily and others will be present to talk about the exciting find.
Artefacts found last year will be on display with both pre-European and early European artefacts present including midden samples, glass, pottery, other smaller adze's and cutting tools.
"The team will have some sample trenches on display and talk through the process and science of unearthing the past, but what's interesting is that it's often what's not found that can tell the biggest story," Emily said.
The toki will be registered under the Ministry of Cultural Heritage protected objects acts and applications for custodianship will be able to be made at the end of the project after the archaeological analysis and report has been completed.
"Finding the toki is a huge honour," said Oriwa of his discovery.
"Its the key to unlocking the past.
"As kaitiaki I am fortunate to have been trained by experts like Emily and Les Mullen our kaitiaki instructor.
"They taught me to be vigilant and to scan the worksite continually for evidence of occupation by our ancestors.
"Communication between the contractors on this site has been awesome.
"They respect what we do as kaitiaki and I am in awe of the skills of contractors like Treescape and Goodmans who we interact with daily."
The archaeological open day will be held on Saturday, 5 School Rd, Te Horo, from 10am to 1pm.