Sonny Bill Williams has committed to playing rugby in New Zealand next year, the only question is where, and the decision looks set to be influence by the All Blacks centre's love for his mother.

Tugging on his heartstrings along with his mother are All Blacks co-coach Wayne Smith and Canterbury Crusaders mentor Todd Blackadder, Williams' agent Khoder Nasser told the Sunday Star-Times.

Nasser's confirmation that Williams will stay in New Zealand another year ended months of speculation over where the multi-talented player would end up, as he was sought by Rugby Union and League clubs around the world.

Williams walked away from a world record five million US-dollar offer from French club Toulon to move home to New Zealand last year on a short-term contract in the hope of making the All Blacks World Cup side.

But his future after the World Cup was up in the air until Nasser told the newspaper Williams feels he owes it to New Zealand to stay at least another year.

He explained: "Sonny feels a moral obligation to stay in New Zealand for another year after the hospitality that the New Zealand public has shown him.

"Mentally, the intention had always been to only stay for a year but he's realised that he owes something to (All Blacks coach) Graham Henry, Wayne Smith and Todd Blackadder," said Nasser.

The Crusaders, Chiefs and Blues are all chasing Williams' signature and Nasser said the money on offer will not be the deciding factor.

Williams' family ties are strong and his mother wants him to play for the Blues, which would base him in his home city Auckland - but a move there would also pit him against All Blacks rival Ma'a Nonu.

The Chiefs will have Smith as an assistant coach next year, while the Crusaders and Blackadder take credit for turning the former League ace into an impressive All Black - so it will be interesting to see who he shows his loyalty towards.

"He has so much respect for the people that have helped him and doesn't want to let anyone down," Nasser said.

"The choice is not an easy one. It's not about money. It's not about who will offer more or anything like that. The choice for Sonny is about people," he added.

Nasser said the New Zealand Rugby Union was also agreeable to let Williams 'pursue his dreams in other sports', indicating he would be continuing his boxing career.

AFP