A significant Māori archaeological site has been extensively damaged by illegal fossickers in the Waitaki District.
Last Friday, up to a metre-and-a-half of digging along creek beds was discovered at Awamoa Creek after previous reports of casual fossicking.
Under New Zealand law, it's a criminal offence to modify or destroy an archaeological site without permission.
Upoko Te Rūnanga o Moeraki David Higgins said Te Awa Kōkōmuka has great significance.
"The site forms part of important travelling routes for early Māori up and down the South Island, linking to coastal and inland networks."
Heritage New Zealand Pouhere Taonga Otago Southland area manager Jane Macknight said it was disheartening to find such blatant fossicking and damage.
It was unclear what had been removed, but it was a loss of knowledge of Aotearoa's heritage, she said.
"For Māori, it's a mahinga kai site, possibly an occupation site. For Europeans, it's the first archaeological dig site in the South Island. (Government Commissioner) Walter Mantell stopped at that site when he was being guided down the South Island by Māori and he removed moa bones from the site," Macknight said.
"There is clear signage warning the public that this site is an archaeological reserve and not to remove items from the site."
The recent damage was "on another level entirely", she said.
"If people are fossicking these sites hoping to find items of tradeable value, then they're probably mistaken in their understanding of why the site is significant and probably carrying out needless damage to the site, and at the same time causing a loss in our stories and in our history."
The site had previously been investigated under an archaeological authority granted by Heritage New Zealand Pouhere Taonga to Te Rūnanga o Moeraki, which revealed it to be a very early mahinga kai site for Māori.
Both group and Waitaki District Council staff are working to assess the ongoing protection of the site which is also subject to coastal erosion.
Anyone who may have knowledge about the recent site damage can contact Heritage New Zealand Pouhere Taonga by email at (firstname.lastname@example.org) or on 03 477 9871.