Former All Blacks doctor John Mayhew confirmed Lomu had died unexpectedly this morning.
"On behalf of the Lomu Family, I can confirm that Jonah Lomu Died this morning, most probably about 8 or 9 this morning" Mayhew said. "The family are obviously devastated, as are friends and acquaintances. "The family have requested privacy at this stage, they are obviously going through a terrible time. "It was totally unexpected. Jonah and his family arrived back from the United Kingdom last night and he suddenly died this morning."
Lomu had been in the United Kingdom with his family as a spokesman for Heineken during the Rugby World Cup.
The bruising winger made 73 appearances for the All Blacks, making his Test debut in 1994 against France in Christchurch.
A star already in New Zealand, it was the 1995 World Cup which made Jonah an international sensation, running over England's Mike Catt and scoring four tries in one world cup game.
Lomu scored 43 tries in the black jersey, before having to quit the sport in 2002 because of Nephrotic syndrome, a rare kidney disease.
The plan was to play again for the All Blacks at the 2007 World Cup, but after stints in Wales, and North Harbour, the comeback never came.
Lomu was made an New Zealand Order of Merit, he also took up body building, and also played for a French third division side.
He suffered a health scare in 2011, pulling out of the Fight for Life charity boxing event with kidney troubles, just seven years after his life-saving kidney transplant.
Nadene Lomu has since released a statement on her late husband.
"It is with great sadness that I must announce my dear husband Jonah Lomu died [overnight]," the statement read.
"As you can imagine this is a devastating loss for our family, and may I ask that our privacy, especially the privacy of our two very young boys, be respected as we take them through this traumatic time."
New Zealand Rugby expressed shock at the sudden death of Lomu.
"We're all shocked and deeply saddened at the sudden death of Jonah," said New Zealand Rugby Chief Executive Steve Tew.
"We're lost for words and our heartfelt sympathies go out to Jonah's family. Jonah was a legend of our game and loved by his many fans both here and around the world."