UPDATED 4.43PM:  A noted Maori leader and academic has died.

Dr Ranginui Walker dedicated much of his life to promoting Te Reo Maori and history, with a particular passion for ensuring historical events significant to Maori were properly documented.

He also made his voice heard by writing several books, and columns in The Listener magazine for nearly 20 years.

Fellow academic Dr Paul Moon said he was an extraordinarily productive researcher and writer, who kept giving seminars and publishing books.

"Publicly he had a reputation of being stern and amendment, but he had a very humorous side to him as well," said Moon.  

"I think the best description of him is someone who's very honest to his beliefs." 

Singer-songwriter Moana Maniapoto said Dr Walker's staunch commitment to Maori sovereignty had a huge influence on political thinking.

"He was labelled an activist and a radical in his time, but he really helped shape the thinking of a younger generation."

Maniapoto spoke to Dr Walker recently and said he was as clear, consistent and committed as he had always been.

"He'd just like get straight to the crux of the issues, cutting through all the fluff and getting to the guts of it."  

Green Party co-leader Metiria Turei said Dr Walker's contribution to New Zealand politics and Maori politics can't be underestimated - particularly his efforts to identify and combat racism.

"It meant that when we felt it we could understand why it was happening and he gave us the tools to combat it. His legacy is going to last for generations and generations to come."

Maori Party co-leader Te Ururoa Flavell said he personally owes a lot to Dr Walker, after studying in his classes at university.

"He was the person that really prodded my conscience and provided me with a background of understanding about issues to do with our people and indeed New Zealand's history."

Labour's Maori Affairs spokesman Kelvin Davis said Dr Walker was a "towering voice" who fought tirelessly for Maori for decades.

Prime Minister John Key said he's saddened to learn of Dr Walker's passing.

Key said Dr Walker was not only an insightful commentator on important historical and contemporary issues, but was also a tireless and passionate advocate for Maori.

Recently Dr Walker was one of the top 10 contenders for the New Zealander of The Year award, due to his tireless efforts and contribution to the Maori community.

He passed away in his Auckland home, at the age of 83.  He would have been 84 tomorrow.