All Blacks back Sonny Bill Williams has re-signed with the New Zealand Rugby Union and made a switch from the Crusaders to the Chiefs for next season.

World Cup winner Williams had been linked to a number of clubs following the tournament, including a move out of New Zealand rugby to French club Toulon.

The 26-year-old has agreed a 12-month deal with the NZRU which also allows him to participate in his part-time professional boxing career.

"We're delighted that Sonny has chosen to continue playing his rugby in New Zealand next year," said NZRU general manager Neil Sorensen.

"He was exciting to watch in Super Rugby this year, and he played an important role in the spectacular Rugby World Cup-winning All Blacks side.

"He's a special player who creates some real excitement and interest in the game with his style of rugby. We're looking forward to seeing him create some more excitement in a Chiefs, as well as an All Blacks, jersey next year."

Williams has been capped for the All Blacks 14 times since making his international debut in 2010.