Mohammad Ghobadloo's defence team is concerned that he may be killed soon after the Supreme Court of Iran dismissed his appeal against his death sentence for "corruption on Earth" charges.
Ghobadloo's attorney, Mahdakht Damghanpour, wrote on Twitter that the court had upheld his appeal against the conviction for murder, but that the appeal against the conviction for "corruption on Earth" had been rejected.
"We have registered the appeal four times, and each time the court has refused to register and accept it," Damghanpour said.
Ghobadloo was charged for his suspected involvement in a car-related attack on police that left one officer dead and five others injured.
Iran's judiciary frequently accuses parties in instances involving alleged espionage or attempts to subvert the regime of "corruption on Earth."
But after months of upheaval over the claimed inappropriate head scarf use that resulted in the death of a young woman in September, courts have started using the accusation against protestors who have thronged the streets in large rallies.
Amnesty International has denounced Iran for the 22-year-old Ghobadloo's trial, which resulted in his death sentence without the presence of his attorneys.
The rights group claims that the protestors' "fake trials" are "intended to scare people taking part in the public revolt that has shook Iran."