Piutau, Israel Folau, Malakai Fekitoa, Vaea Fifita and Seta Tamanivalu can now all play for Tonga while former All Blacks winger Waisake Naholo is eligible for Fiji.
"Approval of this landmark regulatory change is the culmination of detailed and widespread modelling and consultation across the game," World Rugby Chairman Sir Bill Beaumont said:
"We have listened to our membership and players and sought to update the regulation recognising the modern professional rugby environment without compromising the integrity of the international game.
"Any player who wishes to transfer will need to have a close and credible link to their new union, namely birthright or parent or grandparent birthright while meeting strong criteria, including a 36-month stand down period. We believe that this is the fairest way to implement progressive change that puts players first while also having the potential to support a growing, increasingly competitive international men's and women's game."
Isa Nacewa played two minutes for Fiji at the 2003 World Cup as a 20-year-old and tried numerous times unsuccessfully to have the rules changed to allow him to represent the All Blacks.
He said ahead of the vote that it's a pivotal moment for the Pacific nations and would make a "significant change".
"It's been talked about for so long. Dare I say it's been the elephant in the room for the last 20 years," Nacewa told NZME. "But it's groundbreaking. It would make a significant change to a lot of the smaller nations. That's just the plain fact behind it.
Nacewa says having former internationals playing for Pacific nations could only be a positive.
"If the likes of Charles Piutau and Malakai Fekitoa, some of the best players in the world, can give back to their home nation and then bring on youth within and people can learn from them, that just bolsters everything."
The new rule:
From 1 January, 2022, in order to transfer from one union to another under the revised Regulation 8 (eligibility), a player will need to achieve the below criteria:
- The player must stand-down from international rugby for 36 months
- The player must either be born in the country to which they wish to transfer or have a parent or grandparent born in that country
- Under the revised Regulation 8 criteria, a player may only change union once and each case will be subject to approval by the World Rugby Regulations Committee to preserve integrity
