The 23-year-old Riki had a breakout season in 2023 where he played 22 games and established himself as a strong ball runner and iron clad defender during the Broncos' charge to the grand final.
Piakura, 21, had earlier inked his own three-year extension in a week where the Broncos also extended veteran winger Corey Oates for one year.
Riki made a name for himself in 2023 with the improvement in his kick-chase game which developed into one of the best of all NRL forwards.
He has now played 67 first grade games for the Broncos after making his debut in 2020 during the low point of the club securing a maiden wooden spoon.
Coach Kevin Walters said Riki was a key figure in the Broncos roster now and a vital cog in the squad he was building for the future.
"Jordan bought into what we are building here at the Broncos from the very start," Walters said.
"He was one of the first players to commit to stay even when things weren't going so well, and now he has again chosen to stay at the club he loves, which is fantastic new for us.
"Jordan continues to work hard on his game. He does the little things really well and he wants to plat his role for the team. That's exactly the kind of player we want in the Broncos jersey."
Riki is a graduate of the Broncos Academy system and joins a growing list of stars who are signed until at least the end of 2025 that includes grand finalists Payne Haas, Pat Carrigan, Reece Walsh, Kotoni Staggs, Selwyn Cobbo, Kobe Hetherington and Jesse Arthars.
Top 30 squad members Corey Jensen, Deine Mariner, Xavier Willison, Tristan Sailor and Blake Mozer are also on the books for at least another two seasons.
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