Tūhoe tribe is being accused of embarking on a "colonial purge" following a Department of Conservation (DoC) decision to demolish the Aniwaniwa Visitor Centre near Lake Waikaremoana.
DoC recently confirmed it would demolish the 1976 building, which is deemed one of the finest examples of modernist work by the late Hawke's Bay architect John Scott.
Pierre du Toit, owner of Havelock North's Fat Parrot Architecture, told Hawke's Bay Today the decision was backed by Tūhoe in a bid to rid Te Urewera National Park of colonial influence.
"This is a colonial purge by Tūhoe who are using DoC as a scapegoat," Mr du Toit said.
"It's disappointing because the building was designed as a modern marae to bridge the gap between Maori and Pakeha, and that just hasn't happened."
Aniwaniwa has the highest Heritage New Zealand Category One rating. It was "pink stickered" in 2010 by Wairoa District Council after a report found it unsafe.
Mr du Toit said DoC had neglected the structure for years and had "demolished the building through neglect".
DoC declined to comment on its maintenance of the building but said it was "mindful" of the heritage values and was working with Tūhoe and the Te Urewera Board to use salvageable materials in a new Wharehou centre, planned for a different site.
It said an estimated $3 million would need to be spent if it were to restore the building, yet Mr du Toit disagreed, claiming he had received a report for "less than a quarter of that price".
John Scott's son, Haumoana artist Jacob Scott, said the "purging" by Tūhoe was regrettable, given Aniwaniwa was "built for Tūhoe as an extension of the Tūhoe story".
"The old man [John Scott] designed it around that idea. It communicates that without any words being said; the story is just apparent."
He said conflict between local tribal factions made the situation a delicate one.
"Ruapani have a claim on the lake, so Tūhoe are usurping their position. The Crown doesn't want to re-litigate the claim, so that's why it's keen to push this through."
Despite his father's Maori ancestry, Mr Scott said Tūhoe regarded the building as a "headquarters of colonialism".
"They're using DoC as their instrument to get rid of the building."
The NZ Institute of Architects president Christina van Bohemen said she was "dismayed" by the decision.
"DoC proclaims on its website its commitment to New Zealand's unique legacy and enjoins us to pass it on. So why demolish a building that Heritage New Zealand has found to be of outstanding significance?" she asked.
She said the department was using its failure to properly maintain Aniwaniwa as justification for its destruction.
Tūhoe chief executive Kirsti Luke did not respond to numerous requests for comment, while Tūhoe chief negotiator Tamati Kruger could not be reached.
The DoC said it had yet to decide on a date for demolition.