A Kiingitanga spokesperson say he had been in hospital recovering from heart surgery, days after celebrating the anniversary of his Coronation.
The Kiingitanga has confirmed he passed away peacefully this morning surrounded by family.
He was 69-years-old.
“The death of Kiingi Tuheitia is a moment of great sadness for followers of Te Kiingitanga, Māoridom and the entire nation,” the spokesperson said.
"He kura kua ngaro ki tua o Rangi-whakamoe-ariki. Moe mai raa" [A chief who has passed to the great beyond. Rest in love].
He will be taken to Tuurangawaewae marae, and his tangihanga is expected to last for at least five days.
It is likely his successor will be named at the end of the tangi.
Kiingi Tūheitia succeeded his mother, Te Arikinui Dame Te Atairangikaahu, following her death in 2006.
He was the seventh of the line of Pōtatau Te Wherowhero to head the Kiingitanga, which was founded in 1858.
Kīingitanga chief of staff Ngira Simmonds said he believed in the vision of his ancestors and understood his role and duties and wanted to bring unity to Māoridom.
"He served to the very last."
"It's not a conquering monarchy; we're here because we've been asked to be here."
In the next few days, Tainui (the tribes in the Waikato), who look after the Kiingitanga will gather, before being joined by other iwi.
There will be a day set aside for foreign dignitaries.
There will be an election for his successors.
The kiingi will be laid to rest on the urupa with his mother and other kings atop Taupiri mountain.
Kiingi Tūheitia is survived by his wife Te Atawhai and their two sons Whatumoana and Korotangi and daughter, Ngawaihono.
Prime Minister Christopher Luxon released a statement this morning expressing his condolences.
"I will remember his dedication to Aotearoa New Zealand, his commitment to mokopuna, his passion for te ao Māori, and his vision for a future where all people are treated with dignity and respect. I will also remember the kindness he showed me personally whenever I met with him at Turangawaewae."
The Prime Minister is currently at the leaders’ retreat at the Pacific Islands Forum. A formal statement will be made at approximately 12pm NZT.
