Before construction could begin on the new wing of the Sarjeant Gallery, Whanganui kaumatua John Maihi oversaw the blessing and burial of two mauri stones.
The ceremony on May 6 was attended by four local iwi members.
Sarjeant Gallery redevelopment project director Gaye Batty said the dawn burial involved two taonga.
"One [mauri stone] was collected from the Whanganui River to signify a reconnection with a mauri stone that has been buried under the Sarjeant Gallery since 1919 when it was originally constructed," Batty said.
Another stone, a piece of shell rock chipped from the bluff overlooking the Whanganui River and gifted by Ngati Tuera and Ngati Hinearo, was buried in commemoration of lives lost in the Covid-19 pandemic.
"This was previously on display at Sarjeant on the Quay, and is thought to up to one million years old," Batty said.
Batty said the first step in the burial process was iwi choosing where the stone would rest.
"It was decided to locate it at the centre of the new link between Te Pataka Sir Archie Taiaroa and the existing Sarjeant, and it was buried at a level well below any future excavation proposed further along in construction.
"No digging could take place on the site until it was blessed so the ceremony was a critical element in the project programme."
The area for the new wing was blessed to allow the contractor to come on site and prepare the 3m deep hole the day before the dawn ceremony.
Batty said that once the burial was over, the digging rig operators came forward and filled in the hole, observed from a safe distance by the project's archaeologist and site manager.
"Originally the ceremony was scheduled for March 24, the day before lockdown, with up to 40 members of iwi and guests expected to be in attendance including Minister Shane Jones.
"At the end of the redevelopment project, a third mauri stone will be placed above ground and this will come from the mountains, and will be placed by northern awa tribes from Whanganui."