Lomu has not played since April

The All Blacks giant has started dialysis treatment for the chronic kidney condition - nephrotic syndrome - that has affected him since 1996.

Lomu told a New Zealand television station he will need a transplant, and conceded it was "highly recommended" he does not play again after such an operation.

I'd risk everything to live the dream I started Jonah Lomu

But the 28-year-old believes he can still play while undergoing treatment, and hopes to recover fitness in time to play in October's World Cup.

"There's danger in everything," he said. "You could walk around the corner and get hurt by a truck, there's always that possibility.

"A lot of people think I'm being very silly and putting my health at risk and so forth, but to me I'd risk everything to live the dream that I started.

"I wanted to play in the World Cup and win a World Cup. That will complete my life story."

Feature: What now for Lomu?

Lomu became the biggest star in rugby after scoring four tries against England in the semi-final of the 1995 World Cup, scoring eight in total in the tournament.

He grabbed another seven in the 1999 event, making him the leading try scorer in World Cup history.

But on both occasions the All Blacks failed to win the tournament, losing to hosts South Africa in the 1995 final and France in the semi-finals four years ago.