A documentary has been released to mark the two year anniversary of the detainment of a young physics student in Iran.

Omid Kokabee was jailed on 30 January, 2011, after visiting his family in Iran. He had been planning to return to the University of Texas, where he was studying as a doctoral student, when he was imprisoned.

He was charged with "communicating with a hostile government" and making "illegal earnings". The state said Kokabee had been collaborating with Israel's intelligence agency.

He was taken to Tehran's Evin Prison and spent 15 months in jail without a trial. Eventually, he was tried alongside 14 other defendants, 13 of whom had filmed confessions that were broadcast on Iranian state television.

Many of those tried with Kokabee received the death penalty. The physics student has always maintained his innocence. He was convicted in May 2012 and sentenced to 10 years in jail despite there being no evidence of proof.

In the documentary made by students and lecturers at the University of Texas, details of his trial imprisonment are shown.

Arash and Kamiar Alaei, Iranian brothers involved in international HIV research, were placed in a similar situation in 2008 when they were arrested in Iran.

Both have since been freed following public outcry. Arash Alaei said: "I had the honour of being Omid's prison mate for seven months in Evin division 350.

"Omid didn't have any political activity which would make him deserve at 10-year sentence.

Freedom in exchange for collaboration

"He was only a student enthusiastically involved with research, who wanted to help his classmates and his university through academic collaborations.

"When we were in jail he tried to help inmates by teaching English and other topics.

"He was always in good spirits and believed he hadn't done anything against the law or national security."

In open letters written by Kokabee in prison, he says the Iranian government has offered him freedom in exchange for collaboration: "How would it be possible to invite somebody who has been accused of being a spy and cooperating with foreigners to collaborate and to share the most confidential data and secrets of the government?

"What would the insistent calls of the intelligent services and security authorities, the pressuring of my family, the promising me different benefits such as freedom or the continuation of my studies at my former university (University of Texas, Austin) - all in order to convince me to cooperate with them - mean for somebody who has never had any activity outside of university and the research community and who is absolutely unfamiliar with political world?

"What would happen to me if in the future I agree on collaborating with the regime and as a consequence learn about their confidential facts and secrets? What would they take hostage this time to ensure that they can trust me?"

As well as the documentary, the university has also launched two petitions calling for the release of Kokabee.

(Ellen Hutchison/ YouTube)