New Zealand cross-code star Sonny Bill Williams is set to join Super League newcomers Toronto Wolfpack on a two-year deal.
Williams will be a marquee player and has agreed a reported multi-million pound deal to return to rugby league.
The 34-year-old was a member of the All Blacks side who finished third at rugby union's World Cup in Japan last week.
A two-time World Cup-winner in rugby union, he won two Australian NRL titles in rugby league.
The Wolfpack were promoted to Super League for the first time after winning the Million Pound Game last month.
That came just three years after forming, meaning top flight rugby league will be played in North America for the first time in 2020.
The Canadian side start their Super League campaign against Castleford Tigers on 2 February.
Williams will become one of Toronto's two permitted marquee players, which means that only the first £150,000 of his salary will count on the league's salary cap.
Williams has had two spells in rugby league, with Australian sides Canterbury Bulldogs from 2004-08 and Sydney Roosters from 2013-14, winning the NRL title with both.
A back in union but a forward in league, he played in New Zealand's loss to Australia in the 2013 Rugby League World Cup final.
Later that year he was named Rugby League International Federation player of the year, and has been capped 12 times by New Zealand's rugby league team.
He moved to rugby union in 2010 and had spells with French side Toulon and New Zealand Super Rugby sides the Crusaders, Chiefs and Blues.
Williams played 58 times for the All Blacks, winning the World Cup in 2011 and 2015.
He has also boxed professionally, winning all seven of his fights, and held the World Boxing Association International heavyweight title and New Zealand Professional Boxing Association heavyweight title.
'Mind-boggling money for a player who will have rest of Super League punching the air'
Dave Woods, BBC rugby league correspondent
The signing of Sonny Bill Williams is huge for rugby league across the UK and North America.
The Toronto Wolfpack have already built a home following of about 9,000 fans in their home city in their three years of existence.
Signing a player who is arguably the best known in either code will now lift the Wolfpack's profile immeasurably throughout Canada.
The money involved is mind-boggling - an estimated £5m over two years is more than any other side in Super League spends on its entire team roster. And he'll take a share in Toronto Wolfpack.
He's 34 so his most effective playing days may be behind him, but he's still likely to be a huge presence on the field and will undoubtedly be a major influence within the playing group off it.
Unlike any other big name signing from rugby union, he also brings with him a wealth of rugby league experience from his days with the Sydney Roosters and Canterbury Bulldogs before he switched codes.
And the rest of Super League will be punching the air at his arrival. Having a Sonny Bill Williams in the opposition line-up whenever Toronto Wolfpack come to town will undoubtedly put extra numbers on the gate.
This signing also represents a huge personal investment from Wolfpack owner David Argyle and other backers of the club.
After spending millions over the three years it's taken to get the club promoted through the lower tiers of rugby league, this is an explosive statement of intent that they intend to make their mark on Super League now they have reached the top flight.