The horrors visited on tens of thousands of Iranians in the years after the Islamic revolution were spelled out as the Iran Tribunal published its final judgment. Described as “a great achievement... a miracle,” by one of the survivors, the Tribunal found that during the 1980s the Islamic Republic was guilty of the murder of between 15,000 and 20,000 political prisoners.

Inspired by the Russell Tribunal set up by Bertrand Russell and Jean-Paul Sartre to investigate American war crimes during the Vietnam war, the Tribunal, sitting in The Hague, set about documenting and publishing the crimes against humanity committed by the Islamic regime that have been referred to as Iran’s Srebrenica after the massacre by Ratko Mladic’s Bosnian Serb forces on Muslims during the Balkan wars. British QC Sir Geoffrey Nice, a member of the Tribunal’s Steering Committee, told The Independent: “There are a number of such tribunals around the world, but what is particularly striking about this one is that it was started and seen to fruition not by lawyers but by the Iranian diaspora itself, by people who had themselves been tortured.”

It was in 1981 that Iran’s new Islamic government, with Ayatollah Khomeini as its figurehead, rounded on the leftists and others who had come together with the Islamists to bring down the autocratic rule of the Shah two years earlier and gave them two choices: convert or be liquidated.

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Mrs Shekoufeh Sakhi, today writing a PhD thesis in Political Philosophy at the University of Toronto, told the Tribunal how she had been forced to sit blindfolded and motionless in a sort of coffin from dawn to late at night while her jailers bombarded her with Islamist propaganda and recordings of the “confessions” of fellow-prisoners who had been broken by the torture. Sir Geoffrey Nice described her as “a quite inspirational figure”.

“In the 1980s the Islamic Republic of Iran went about arresting, imprisoning and executing thousands upon thousands of Iranian citizens because their beliefs and political engagements conflicted with the regime,” the judges wrote. “The religious fervour of these crimes makes them even more shocking: for instance, a woman’s rape was frequently the last act that preceded her execution in Iran, as under the ‘Sharia’ law guidelines, the execution of a virgin female is non-permissible.”

As Mrs Sakhi explained, there was nothing haphazard or unconsidered about the regime’s long reign of terror. As a left-wing 14-year-old in Tehran she had taken part in the uprising against the Shah alongside the Islamists, but by 1982 things had changed. “Iran was now at war with Iraq, and now the mood of the regime was, ‘if you’re not with us you’re against us.’ Revolutionaries like me came to be seen as counter-revolutionaries and fifth columnists. They rallied their base support against us and divided the country in two.”

In June 1981 there was a wave of arrests and summary executions. Ms Shekoufeh went underground but the following February the Revolutionary Guards arrested her. “It was amazing and bewildering,” she recalled. “Those who had been in jail during the Shah’s time said this was much worse. The big difference was that they weren’t going after big organisations – my organisation had already fallen apart – but were collecting everybody who had the motivation to be ‘different’. The jail was so full of high school students you could hardly move. The project was mass conversion.” The executions had been a way of softening up the youth for conversion.

Those like Shekoufeh who proved stubborn were given the “coffin” treatment – nine months of sensory deprivation and complete immobility. “It was a horrible psychological torture,” she said. “You couldn’t move, talk, cough, sneeze, if you did they’d beat you up. There were constant sermons and Islamic teaching classes through the loudspeakers. The whole point was to empty the person of their own identity, making you an empty shell then filling you up with their garbage. After two or three months I felt I was losing my mind, losing control of my sense of reality. A lot of people had nervous breakdowns.”

Sir Geoffrey Nice commented, “The Tribunal is a very major thing. The most important thing is that people can say what happened, they can put it on the record. Now the UN could be pressed to have their own commission of enquiry.” Iran’s government was invited to the Tribunal but neither replied nor took part.

Ayatollah rejects US talks

Iran’s supreme leader has strongly rejected proposals for direct talks with the United States, effectively quashing suggestions for a one-on-one dialogue on the nuclear standoff and potentially other issues.

The statement posted on Ayatollah Ali Khamenei’s website echoes previous remarks opposing bilateral talks with Washington in parallel with stop-and-start nuclear negotiations with world powers, including the US, which are scheduled to resume later this month.

But the latest comments marked Khamenei’s first reaction since the idea of direct talks received a high-profile boost earlier this week from US Vice President Joe Biden during a security summit in Munich attended by Iran’s foreign minister.

Khamenei’s statement also could spill over into the negotiations in Kazakhstan later this month between Iran and a six-nation group comprising the permanent UN Security Council members plus Germany. His apparent references to US sanctions - saying Washington was “holding a gun” to Iran - suggests Iranian envoys will likely stick to demands for relief from the economic pressures before considering any nuclear concessions.

The US this week further tightened sanctions on the Islamic Republic, which have already cut Iran’s oil revenue by 45 per cent. AP