The deal will see the Fijian winger stay in the nation's capital until the end of the 2024 season. While Valemei hasn't been a permanent fixture in first grade this season, he has shown constant improvement during his time in Ricky Stuart's team.
After playing ten NRL games last year, he has played four so far in 2021 and will turn out in green against the Titans this weekend.
Scoring a try against the Broncos in Round 14 has been the highlight of his season, but he has also scored two tries in three games at reserve grade level this year.
Valemei is following in the footsteps of other Fijian wingers who have cut a path for themselves in the NRL over the past few years. Maika Sivo and Suliasi Vunivalu headline the crop of talent from the island nation.
For a player who only made his reserve grade debut last year, Valemei has fast become a fringe member of the first-grade squad and will look to turn that into a full-time starting role over the next 24 months.
Valemei said he has developed greatly since arriving in Canberra.
“I’m very happy to remain here for the next three years,” Valemei said.
“Since coming over from Fiji the Raiders have been fantastic for my development and I’m looking forward to continuing playing here and developing even further."
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CEO Don Furner said Valemei's signature was another positive move for the club.
“Semi has shown really positive signs since making his NRL debut last season and he’s a player we know still has plenty of improvement and development ahead of him,” Furner said.
“It’s another show of faith in the club with another young player committing for an extended period which is really pleasing."