The nonbinary singer Nemo won the high-camp contest, during a night that included pro-Palestinian demonstrations outside the arena and fireworks onstage.
The competition’s organizers said that Swedish police were investigating the singer Joost Klein and that it would be inappropriate for him to take part in Saturday’s final.
Campaigners have unsuccessfully urged the Eurovision Song Contest to ban Eden Golan because of her country’s war in Gaza. “I won’t let anything break me,” she said.