"Two months on, I still feel the pain in my ribs, kidneys, testicles and my left ear … but even worse was the mental torture … I was humiliated and morphed into another person. Even neuro pills do not work anymore and I keep suffering from severe seizures," wrote activist Esmail Bakhshi on his Instagram account. Bakhshi was a union leader and worker at a sugarcane factory in Iran's southwestern town of Shush, which was rocked with protests and strikes last year in response to months of delayed wages. 

He was released from detention Dec. 12, after being held for several weeks on national security charges. In the same Instagram post, Bakhshi complained that intelligence officers wiretapped his phone long before he was arrested, listening in on private conversations between him and his wife.

His public testimony on the torture he endured in detention has shocked Iranians, triggering widespread reactions across the political spectrum. Now, he has openly challenged Iran's intelligence minister to a live televised debate.

In response to the backlash, Iran's judiciary dispatched a special team to the town of Shush to investigate the torture claims. President Hassan Rouhani has also directed officials to probe "the violence" in a "speedy and precise" manner.