According to New Zealand media, Lauaki, who was capped 17 times for the All Blacks, passed away in Auckland over the weekend surrounded by family, having apparently suffered kidney failure.
The Tongan-born was married to Stephanie, from the Mataroa family from Arorangi.
Their intimate marriage ceremony in 2014 at the Crown Beach Resort and Spa was attended by rugby union and league stars including his former All Blacks and Chiefs teammates.
Lauaki was lately based in Rarotonga and played for the Arorangi Cowboys and Bears teams in the domestic rugby union and league competitions.
Yesterday, Cook Islands Rugby Union chief executive officer Ben Koteka said they were saddened by the loss.
He said Lauaki contributed to the development of rugby here, playing for the Cowboys and running tag-rugby clinics for children.
Koteka said he also trained an age-group team, passing on the knowledge to the aspiring rugby players in the Cook Islands.
“He will be sorely missed by the rugby fraternity here. We are saddened by his untimely death, he was really young,” Koteka said.
“He was a humble person and helped grow rugby in the Cook Islands. He was also a big inspiration for the other players when he played for the Cowboys in the local competition.
I believe rugby here benefited a lot from his experience and expertise. It is a sad loss for the Cook Islands and the global rugby fraternity.
Our heartfelt condolences to his family and friends here in Rarotonga and abroad.”
Lauaki made his All Blacks test debut against Fiji in 2005 and went on to play 17 tests for his country until 2008.
The robust flanker/number eight who also played 11 matches for the Pacific Islanders team last played professionally for French football club Aviron Bayonnais in 2012.
New Zealand Rugby chief executive officer Steve Tew in a statement expressed his condolences to the family.
“We are incredibly saddened by this news, as will be many who have known Sione through both his rugby and Tongan community connections.
It is always sad to lose a member of the All Black community, but with Sione passing at such a young age it will be felt with an even greater sense of tragedy amongst his former team mates, fans, family and friends.”