In an open letter to the United Nations, Nizar Zakka, the Lebanese citizen who was incarcerated in Iran for four years on the charge of espionage, asked for UN’s effort in releasing all the hostages in Iran.

Zakka released this letter on the “fourth anniversary of his kidnapping.”

The former political prisoner describes what he went through in the past 4 years and says the motive of the Islamic Republic officials from his arrest was to use him as a pawn in their campaign against the atmosphere of openness that was forming in the country.

He talks about the hardships of prison and the suffering “you wouldn’t understand until you experience it.”

In his letter Zakka confesses that the prison experience in Iran has changed him and after four years he wants to be away from everyone, “even from his own family.”

“I have lost my job and everything that I worked for in the past 30 years,” Zakka says.

He goes on to say that he will use his great pain to serve the cause of peace and will try everyday to draw more attention to the problems of hostages and prisoners who are incarcerated arbitrarily.

The letter calls on the secretary-general of the United Nations to “use all necessary measures to release the hostages from all prisons, specifically in Iran.”

Nizar Zakka was arrested by the Iranian security forces in the September of 2015 after being invited to Iran for the fifth time by Islamic Republic officials.

Iran has arrested a large number of dual citizens on the charge of espionage in recent years, including American-Australian, Iranian-American, American-British, and French-Iranians.