All Black Sonny Bill Williams is returning to rugby league in Australia after two years of playing rugby union in New Zealand.
He told a news conference in Hamilton on Monday he would join an undisclosed National Rugby League club in 2013 after playing a season of rugby union in Japan in its Top League competition which begins in September.
Williams, 26, currently plays for the Hamilton-based Chiefs and will take up a lucrative 10-match contract with the Panasonic Wild Knights following the Super Rugby tournament.
He has played 17 Tests for the All Blacks and at least 20 Super Rugby matches for the Chiefs and Canterbury's Crusaders.
Williams says his return to league comes following a handshake deal made four years ago, although he now has some regrets as he has enjoyed playing rugby in New Zealand.
He says he would have preferred to have stayed with the Chiefs and All Blacks beyond this year if he had not made the earlier commitment.
The Sydney Roosters are widely tipped to get Williams. However, the player will not name the NRL club, as nothing has been signed.
Williams says his main priority now is to help the Chiefs secure the Super 15 title and is not ruling out returning to rugby in New Zealand one day, possibly in time for the 2015 Rugby World Cup.
"I'd love to if things work out maybe one day come back. But in saying that, I'm not gonna hold my breath because there's some great players here. Those players coming though deserve all that they get. I've chosen my path and now I gotta walk it."
All Blacks head coach Steve Hansen says it is a shame New Zealand rugby is losing Sonny Bill Williams but respects his decision, saying his contribution - however short-lived - has been immense.
New Zealand Rugby Union chief executive Steve Tew says the midfielder would be welcomed back with open arms.
Williams says he also plans to continue his boxing career.