FILE- In this April, 9, 2007, file photo, Iranian President Mahmoud Ahmadinejad speaks at a ceremony in Iran's nuclear enrichment facility in Natanz, south of capital Tehran, Iran. Tensions between the U.S. and Russia have been rising. The countries have been at odds over Syrias civil war, Irans nuclear program and Russias crackdown on domestic opposition. U.S. officials are uneasy about what they see as a more assertive foreign policy by Vladimir Putin, who returned to the Russian presidency in May. (AP Photo/Hasan Sarbakhshian, File)

I visited him in 2005 at his home in northern Tehran, facing the Alborz Mountains. He is the longest held prisoner of Iran, sometimes referred to as the Iranian Mandela.

He was on a leave of absence, which is part of a prison furlough system in Iran. His name, Abbas Amirentezam, should be familiar to anyone who knows the history of the U.S. Embassy take-over in 1980 and the plight of the American hostages held for 444 days. He is not referred to in the film Argo.

Amirentezam became the other hostage. He was courteous and gracious, a real gentleman with a soft voice. It was hard to imagine that he had been in prison for so long. He had a smile on his face and resoluteness in his demeanor.

Following the Revolution, as the deputy PM to the provisional government and its spokesperson, he met with American diplomats in Sweden. He had been asked to begin talks with the U.S. -- normal procedure after a change in government. Amirentezam had acted like the diplomat that he was. A forged lettersigned by Kamal Kharazi, deputy foreign minister, summoned him back to Tehran where he was branded as a spy for the Americans.

The Swedish foreign minister had warned him, "Don't go back to Iran, there is a plot against you." But he did. He hadn't done anything wrong. The role he next played in the Embassy take-over came to haunt him as well. "I was informed that the American Embassy personnel had been taken into custody, that some passports had been confiscated, and that the premises had been ransacked. It was midnight when I called Mr. Bazargan and woke him up. I asked him what we were to do. He replied, 'Do whatever you can.'"

Unfortunately, we did not have a military or security unit at that time. A few dozen militant hooligans had taken over many of the ministries so there was no viable security apparatus after the Revolution. These men were essentially running the show. We took care of the immediate problem and returned the passports to their rightful owners." He adds," In the morning, Mr. Sullivan [U.S. ambassador to Iran] and Mr. Stempel [political officer] came to see me and gave me a letter which addressed me as 'Dear Mr. A.E.' They thanked me for my assistance with the passport. This letter was in fact the basis for my arrest, the most incriminating aspect being that the U.S. Ambassador had addressed me as "Dear"! They claimed that the use of this specific word implied that U.S. officials had close ties to me and considered me one of their own!"

Arrested in 1980 at the foreign ministry office, and tried in a kangaroo court, Amirentezam spent 555 days in solitary confinement -- first sentenced to death and then to life in prison. He was accused among other things -- of relaying information to the Americans, of facilitating the departure of the Shah's officials, of wanting to dismantle the Assembly of Experts and of rejecting the principle of velayat faqih (the rule of clerics).

Bazargan, in vain, testified on his behalf. Years later, the judge who had prosecuted him, sent him a note of apology. Too late, I might say.

Now in his early eighties, with many ailments, he has lived to tell the tale of his incarceration. Recently, he was hospitalized again. He suffers from diabetes. Years of mental and physical torture have taken their toll on him.

While in prison, he had exposed the crimes of Lajevardi -- Evin's prison warden, known as the butcher of Evin -- during a visit by the U.N. human rights commissioner. In retaliation, he was put on a back of an open truck and driven around for hours in the frigid hills of Evin. As a result, he lost his hearing in one ear.

In 1988, he witnessed the emptying of prison cells as hundreds were taken to the gallows and executed. He said those were the worst times of his life. Others came and left but he remained -- for nearly 26 years.

"The worst time was when I was with other prisoners and witnessed many of my cell mates being taken and executed one-by-one, without any trials or jury. We were 350 people in our ward -- 342 of them were executed, ranging in age from 20 to 70 years."

Amirentezam, who was educated in the U.S. (Berkeley) and in France, is an engineer by profession but since his incarceration he has never been able to work or conduct any business. As a young student, he had handed a defiant letter to Vice President Richard Nixon who had come to visit Iran in 1963. He, like many, was a supporter of Mossadegh.

Amirentezam has never given up his passion for politics. Free on probation, he is currently a board member of the National Front. He calls the recent sanctions, "A terrible human tragedy," creating an unjust and an unbearable situation for the people of Iran. "Their impact will be long lasting," he adds. He has repeatedly warned against a military attack on Iran.

Over the years, Abbas Amirentezam has also called for a free referendum in Iran to be monitored by the United Nations. "The only way to achieve a true and viable democracy in Iran is through a national vote through which the people can determine their desired form of government," he says in a brochure he published nearly a decade ago.

Amirentezam remains an Iranian hero. When after many years in prison he paid an unannounced visit to Tehran University, thousands of students rose in his honor. "I will remain beside you and with you until the very end of my life," He told the crowd. All through this ordeal, he has asked for one thing -- that all false charges against him be dropped.

He has been waiting for justice for 33 years, so far to no avail.