It was during Friday's gig at the festival in Umeå that the group showed an animated video on the big screens in which they hit and kicked Sami people in a video game-like fight.
The incident has now been reported to the police for incitement against an ethnic group, SVT Västerbotten reports.
The police confirm to SVT that a preliminary investigation is underway, but Brännbollsyran's festival manager declines an interview.
Roc Boyz previously attracted attention in Norway after the group sabotaged a Sami protest in Oslo in 2023. The incident occurred against the backdrop of an increase in harassment of Sami people, as documented in a report from Amnesty International Norway.
