Her late husband was known as the man who got things going while she earned a reputation among whanau and Tainui as the woman who made sure things were finished.

Lady Raiha Mahuta, Tainui's co-negotiator for its $310 million Waikato River settlement, passed away early yesterday morning just hours before the iwi signed a joint management agreement over the river with the Waikato District Council at Ngaruawahia.

The 67-year-old Lady Raiha had suffered from myelofibrosis, a rare bone marrow disease, and had been having regular blood transfusions.

The oldest of her five grandchildren, Huirama Matatahi, said yesterday that despite her illness "Nana Rai" continued to work hard, meeting last week with Prime Minister John Key and Treaty Negotiations Minister Chris Finlayson to discuss the timeframe for the Waikato River settlement.

"That was her, right up until the day she died, working hard, she was always so precise," he said.

"My koro [the late Sir Bob Mahuta] would always get things started whereas Nana Rai would always make sure things were finished ... and she made sure things were done in an excellent manner," he said.

Lady Raiha's body was taken to places close to her heart around the Waikato before she arrived at Turangawaewae Marae yesterday afternoon. Her close friend and relative Rina Ngataki said Lady Raiha first met her in the kitchen at Turangawaewae Marae in the 1950s.

Mrs Ngataki said Lady Raiha was "someone who would get on with everyone".

"But she was also a person who would stand her ground and if she knew her kaupapa [purpose] was right she would not be swayed," she said.

"She was steadfast and we always admired her for that, particularly after Sir Robert passed away [in 2001]."

Former Minister of Maori Affairs Koro Wetere said his association with Lady Raiha and Sir Bob began shortly after the pair were married at Waahi Pa in Huntly in 1963.

He said Lady Raiha was instrumental in developing many of Tainui's self-determination policies and bodies the iwi now has in place. "There is no doubt in my mind she made huge contributions," said Mr Wetere.

"History will rewrite itself showing she followed her late husband in pursuing excellence and self-determination for our people."

Maori Party co-leader Tariana Turia said she admired Lady Raiha's involvement in Maori access and Maori business development in the 1980s when both were engaged in job creation in their respective regions.

Lady Raiha commanded respect from the Crown on Treaty matters and for her commitment to principle, tempered by the best interests of her iwi and the nation.

She said that Tainui, which has been rocked by the sacking of Waikato-Tainui Te Kauhanganui chief executive Hemi Rau, needed to put its infighting behind it.

Lady Raiha is lying in state at Waahi Marae until Friday morning when her body will be taken to her ancestral land at Karetu Marae, near Kawakawa in the Far North, where she is to be buried. Sir Bob Mahuta is buried at Hopuhopu in the Waikato.

Lady Raiha is survived by son Tukaroto and daughters Nanaia, Waikato Tainui MP, and Tipa.

Maoridom in need of new voice

Lady Raiha Mahuta's death leaves King Tuheitia with an important decision to make as to who will represent him in the tribe's political sphere.

Hugely loyal to the Kingitanga the 67-year-old's service to the kaahui ariki, royal family, was unwavering.

Lady Raiha was Tuheitia's appointment to the tribe's executive board Te Arataura, a role she continued from his mother the late Te Arikinui Dame Te Atairangikaahu.

The tribe's constitution enshrines a kaahui ariki representative to sit alongside 10 other members who are drawn from an elected parliament. Two possibilities for a replacement could come from Tuheitia's own whanau.

Tuheitia's elder sister Heeni Katipa was seriously considered as the new monarch when Dame Te Ata died in 2006 before iwi from around the country finally settled on Tuheitia.

Maharaia Paki is another who could add a fresh dimension to the board. He is the king's younger brother and has worked with youth and is known as a hard worker.

Both are well liked and respected. Waikato-Tainui's executive Te Arataura chairman Tuku Morgan could also be a contender.