When the anti-regime protests kicked off in September 2022, Mr. Salehi, like many Iranians, found he couldn’t sit on the sidelines. Despite the risk of returning to prison, he uploaded videos of his peaceful participation from the streets of Shahin Shahr and recorded two songs highlighting the bravery and plight Iran’s people. In essence, the artist was now living his art.

“We come to streets like ghosts and become a nightmare for the government,” he rapped in “Battlefield,” during the height of the demonstrations. “We see the light after this hell. Neither suppression nor execution can stop us. We shout and go forward. Call us roaring fighters.” In the video for “Fortune,” he confronts the clerical establishment directly, sitting across from an anonymous official representing the Islamic Republic and predicting its demise by reading coffee grinds.

Knowing he faced arrest again, Mr. Salehi left his home in Shahin Shahr, and with the help of friends, reportedly moved from one safe house to the next. Not long after his arrest, an alleged confession video aired on state television. In it, he was blindfolded, clearly under duress and with bruising to his face. He claimed he had “made a mistake.” But his family and fans said he was tortured — as has happened before when such videos were recorded by the Iranian intelligence apparatus. They now believe he needs urgent medical treatment.

As the protests gripped the world’s attention, European lawmakers selected individual Iranian political prisoners and highlighted their cases. A member of Germany’s Parliament, Ye-One Rhie, chose Mr. Salehi. According to Ms. Rhie, the rapper has since been charged with “insulting the leadership,” “propaganda against the regime,” “cooperation with hostile governments,” “inviting people to kill and disturb,” and “corruption on earth.” That last charge, which is used against actual or perceived dissidents to squash any opposition to the Islamic Republic, could carry the death sentence.

Ms. Rhie said that Mr. Salehi was in solitary confinement, and has had limited contact with his lawyer since his arrest. There has been no due process in his case, she said, and a court date hasn’t been announced. “Should one be set, however, we can expect not a trial based on the rule of law, but arbitrariness and terror,” she wrote in an email to me.