Ayatollah Khamenei made the demand in a letter to Judiciary Chief Ayatollah Sadeq Amoli Larijani.
“The news of the crime in one of the schools of western Tehran caused grief and regret. It is appropriate to immediately mete out divine punishment after the trial,” the Leader wrote.
The deputy headmaster of a private boys high school accused of harassing students was arrested by police on Tuesday. The arrest was made following complaints by the families of several students.
The shocking news of widespread sexual abuse has prompted outrage among Iranians, particularly parents who fear the same fate could await their children.
Education Minister Mohammad Bathaei said the school had recruited the perpetrator without passing due legal process.
The minister vowed to tighten monitoring of the recruitment process in schools.
The head of the school was also sacked by the Education Ministry following the scandal.