Northland Rugby Union operations manager Greg Shipton said Mr Kini was an absolute legend among the Northland rugby fraternity and his death would hit many people hard.
"Bill was just awesome and an absolute legend for the boys. He'll be really missed and the players and union will be marking his death," Mr Shipton said.
Mr Kini had tremendous physical and mental strength that was an inspiration to the Taniwha's players, he said.
"He was a legend, no doubt about it."
Mr Kini's death would be marked by a minute's silence and the Northland ITM Cup team wearing black armbands for the game against Waikato today, and another minute's silence in the team's first home game of the season against Manawatu at Toll Stadium, Whangarei, on Wednesday.
The NZRU and Sky TV have given permission for the minute's silence before the games. A lifelong passionate supporter of rugby, Mr Kini never achieved his dream of playing for the Maori All Blacks but it was his big mitts and light feet that saw him became a champion boxer in his young days.
He won eight New Zealand heavyweight titles and Commonwealth Games silver and gold medals, feats that saw him become one of the inaugural inductees into the New Zealand Maori Sports Hall of Fame in 2004.
He was awarded that legendary status alongside fellow Northlander Sid Going, Pat Walsh, Mackie Herewini, Waka Nathan, Manga Emery and the late George Nepia.
With his trademark humility, Mr Kini said at the time, "all these other people are legends. I was quite amazed to be asked to be in it with them."
His boxing wins had been unequalled by a Maori sportsman in his day, but he was not out of his league among the rugby greats. He had captained the Auckland Maori team and his team won four Gallagher Shield titles when he played as a prop for Otahuhu in the early 1960s.
Mr Kini started boxing as a 15-year-old in Southland, winning 10 out of 10 fights in his first year and his first national title at the age of 20, in 1957. Although small for a heavyweight, he dominated the New Zealand ring for 10 years, but he also played rugby throughout his boxing career.
"Rugby was my game," he said.
While Northland became the Southland-born man's home and rugby his career, he continued to teach Northlanders to box.
Other sports organisations have also spoken in tribute.
"A mighty Kauri has fallen," said Sport Northland chief executive Brent Eastwood.
"Bill was a fanatical sportsman who strode across a number of sports both as a high performing competitor and then as part of the support crew. He will be sadly missed on the Northland sports landscape."
