A SFO spokesman confirmed serving search warrants and said the case was being formally investigated – a move requiring SFO director Julie Read to "suspect that an investigation into the affairs of any person may disclose serious or complex fraud".
The spokesman was unwilling to comment further, citing the need to "protect the integrity of the investigation and those involved".
The SFO typically handles cases involving frauds of more than $5 million, but has proved willing in the past to lower that bar when public or charitable funds – Ururangi received around $2m annually from Tainui charities, although it is not suggested that an amount that high is under investigation – were involved.
Maori Television reported yesterday's search of the King's offices at the Endowed College Buildings in Ngāruawāhia saw SFO investigators seize documents and computer hard drives.
The raid represents a significant development for the politically and culturally sensitive Kiingitanga, but was met with mostly silence by tribal authorities.
Request for comment from Tainui's tribal executive were not answered by publication time, and a similar requests to Ururangi's chairman, accountant Peter Rogers, went similarly unanswered.
Calls to Ururangi's other trustee, Helen Kotua - Whakaruru's ex-wife - were answered by someone who declined to identify herself, who before handing up said "sorry, sir, not interested" when asked about Ururangi.
Former Tainui chairman Tukoroirangi Morgan welcomed the SFO investigation, and said he hoped it quickly got to the bottom of allegations.
Morgan said the developments raised particular questions for Ururangi's trustees Rogers and Kotua.
"What have they been doing in the surveillance and management of funds at Ururangi? If we're talking about the misappropriation of funds and wrongdoing, all of them should be held accountable," he said.
"Until the lid is lifted, and we get a sense of the scale and the seriousness of the allegations, and then have brought before the courts, only then will we be secure and confident on how our tribal money is being spent."
Acting Prime Minister Winston Peters said he could not comment on any details relating to the raid. He had been advised of it at about 1pm, shortly after news broke.
"I could come to a lot of conclusions but I shouldn't. I've got to wait and find out what happened here."
Hauraki-Waikato MP Nanaia Mahuta said "The tribe will be watching with serious anticipation of where this investigation that might lead."
She called on Tainui to put in place "further oversight or protection mechanisms" around funding to the Kiingitangi while the investigation was ongoing.
In 2015 Ururangi was the subject of an adverse Charities Service investigation that warned further problems could see its charitable status revoked.
That report, obtained by the Herald last year, detailed the King's $350,000 annual salary and raised concerns about 114 transactions between 2012 and 2014 totalling $120,691, relating to the purchase of jewellery, clothing and beauty treatments and almost $90,000 in cash withdrawals.
