"The entire USM Sapiac club is shocked by this tragedy, and has a thought for his wife, his children, his teammates, and more generally, all club lovers. Kelly was a player very appreciated by all, his joie de vivre was infectious and radiant," the club said in a statement.
"Today we lost a player, a friend, a brother."
Meafua played on the sevens circuit for Samoa before heading to France to play for Narbonne in 2015. He joined Montauban last season and scored eight tries in 24 Pro2 matches this year.
All Blacks prop Karl Tu'inukuafe, who played alongside Meafua at Narbonne, posted a tribute to Meafua on his Instagram page.
'We will miss you my uso," he posted.