The sister and brother-in-law of a Marine jailed in Iran shared the graphic details about the torture that he's faced in prison on tonight's “On The Record.”

Amir Hekmati has been imprisoned in Iran for three and a half years. Iran convicted the Marine veteran of espionage, though his family says he was just in Iran to visit his grandmother.

Hekmati's brother-in-law Ramy Kurdi and his sister Sarah Hekmati told Greta Van Susteren about the brutal and harsh conditions that the former Marine is under in the Iranian prison.

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"He has no idea what's going on in his own world," Kurdi said. "He was in solitary confinement. The one thing that people miss, I walk by rooms, whether it be a closet or just a storage space, and I see a one meter by one meter squared area and my heart drops. It still does. They put him there for months."

Kurdi added that he only received a 10 minute break each week to stretch his legs. 

Sarah Hekmati explained that since her brother has been imprisoned, he has been tasered, put in stress positions, drugged with lithium and whipped on his feet.

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She said that her brother has lost over 30 pounds since being in prison.

Sarah added that her brother begged in court for Iranian officials to show him the evidence that validates their decision to sentence him to death. She said they didn't show him any evidence at all.

Watch the full interview above.