A large crowd gathered at Eden Park on Monday to farewell late New Zealand great Jonah Lomu in a public memorial service.

Lomu, one of rugby's biggest ever stars, died unexpectedly at the age of 40 on November 18.

Thousands gathered at the Auckland stadium to farewell Lomu, with tributes paid by the likes of former All Blacks coach John Hart and New Zealand prime minister John Key.

"It's a privilege to pay tribute to Jonah today," Key said via video.

"He meant so much to his family, to his community, to his former team-mates and to his fans here in New Zealand and overseas.

"Everyone recognised Jonah as an outstanding rugby player. He was respected and admired all around the world and rightly so.

"But it was his actions off the field that I will remember most fondly. His sportsmanship was unwavering.

"I was at the World Cup in 1999 when the All Blacks lost the semi-final to France. Despite his deep disappointment, Jonah remained on the field until he had shaken the hand of every single French player.

"More often than not, he was the last player standing on the sidelines signing autographs for young fans. That was Jonah."

Lomu played for the All Blacks 63 times and became a global superstar because of his power and speed as a winger.