After the downing of the Ukrainian Airlines flight by the Revolutionary Guards, large protest rallies and vigils took place in many parts of Iran. Following the protests, many who took to the streets or expressed their views on social media were arrested. Bagheri is a social media activist who was arrested on January 20, 2020. He had also previously converted from Islam to Zoroastrianism.

He was transferred to the Greater Tehran Prison (known as Fashafoyeh) on February 9, after being interrogated in a Revolutionary Guards safe house near Seoul Street.

A well-informed source told Human Rights Reporter in Iran: "The Revolutionary Guards Intelligence agents from Sarollah base arrested Kourosh Bagheri on January 20 of this year. They transferred him to a Revolutionary Guards safe house near Seoul Street and interrogated him. Kourosh was denied the right to make phone calls or to see his family in any way during that time. But today he was transferred to the Fifth Brigade, Unit 2, Hall 2, Greater Tehran Prison."

Bagheri went on a hunger strike on March 16 in protest of his and other prisoners' conditions. "Our situation is dire," he said, describing the condition of prisoners during the covid pandemic. “We are treated like the living dead. The doors of the ward are closed and we are not allowed to leave the ward and communicate with our families. Three prisoners have died in the last week in the Fifth Brigade of Fashafoyeh Prison, where we are prisoners."

According to an informed source, “Bagheri comes from a poor family. He is a carer for his elderly mother. Now that he is in prison, his mother is in a difficult situation, and despite many promises, the court is refusing to change his detention order." Bagheri and his family live in Shahr-e Rey.

While in Fashafoyeh prison, Bagheri was informed that a bail of 500 million tomans had been set for his temporary release. Officers also searched Bagheri's house and found several liters of beer, for which a separate bail of 300 million tomans had been set. He therefore has remained in prison.

Bagheri’s case was referred to Branch 15 of the Revolutionary Court of Tehran on May 11, 2020. Judge Salavati questioned him about the "conversion" of the accused to Zoroastrianism and asked him questions about "insulting [Supreme Leader] Ali Khamenei."

On August 27, 2020, according to a verdict issued by Branch 15 of the Revolutionary Court, he was sentenced to two years in prison on charges of "insulting the supreme leader" and to one year in prison on charges of "propaganda against the regime."

Also, for the second part of the case related to having a few liters of beer at home, Bagheri was sentenced to 40 lashes for "keeping alcoholic beverages” in a hearing held in Branch 107 of the Second Shahr-e Ray Criminal Court on July 14.

Bagheri's two-year sentence began on January 20, 2020.

He was pardoned and released from Greater Tehran Prison on July 10, 2021, after spending nearly one year and six months in prison.