When Shahrzad Kariman finally saw her imprisoned daughter Shiva Nazar Ahari earlier this month, it was for a brief moment outside the Tehran courtroom where the 26-year-old human rights campaigner had been brought. "We could see her for a few minutes," Kariman told the International Campaign for Human Rights in Iran last week. "Just enough to hug her. But we couldn't ask her how the court session went… We didn't know what the charges were prior to the court session."

The charges against Nazar Ahari are among the most serious that can be levelled in Iran: muharebeh (enmity against God), a crime, in theory punishable by death, originally intended to be used against armed gangs and pirates, not dissidents.

Nazar Ahari is also charged with assembly and collusion aiming to commit a crime, propagating against the regime and disrupting public order. But perhaps most dangerous among the allegations – strongly denied both by her family and her organisation, the Committee for Human Rights Reporters – is of "relations" with the banned Mojahedin e-Khalq group, which is accused by the Iranian regime of terrorist activities. Her family says that she deplores the organisation.

Arrested twice since the disputed Iranian elections in June 2009 and held in the notorious Evin prison, in north-west Tehran, Nazar Ahari has been kept largely incommunicado since December, when she was arrested with several other women activists on her way to the funeral of Grand Ayatollah Hossein Ali Montazeri in the city of Qom. Also detained was Mahboubeh Abbasgholizadeh, another prominent women's rights activist and film-maker, who has since left Iran and was sentenced in absentia to two-and-a-half-years in jail and 30 lashes for her part in a 2007 protest.

For the 15 months since Iran's stolen elections, the faces of these women and others like them have been visible from Paris to New York, in London, Berlin, Sydney and the Hague.

Their pictures have been held aloft at demonstrations, appeared on human rights websites and are plastered almost daily across newspapers and television screens. They have joined the faces of other Iranian women who, through their activism or by dint of becoming victims of the regime, have come to be the most visible symbols in the west of the wider political and social oppression in Iran under its conservative president, Mahmoud Ahmadinejad.

Then there are the images of the dead, such as Neda Agha-Soltan, shot on 20 June 2009 while attending an opposition demonstration to protest at the theft of the Iranian election by Ahmadinejad and his supporters.

If female activists have been prominent, so too have women threatened with death, such as Sakineh Mohammadi Ashtiani, the 43-year-old mother-of-two thrust to international attention after she was sentenced to being stoned to death for adultery.

And if Mohammadi Ashtiani is not an activist but a victim, her shocking case has become a lightning rod for activism for Iranian human rights, an example of how women are treated in the Islamic republic and the failure of its judicial system. This has been seized on by film stars and celebrities such as Colin Firth, Emma Thompson and Carla Bruni, the wife of France's president, Nicolas Sarkozy, by politicians such as foreign secretary William Hague, and by institutions such as the European parliament and the Vatican.

The consequence has been that some names and pictures have become as recognisable as those Iranian women internationally renowned before 2009, such as Shirin Ebadi, the Nobel prize-winning human rights activist.

There is a simple reason why the cases of those women being persecuted for their activism and the case of Mohammadi Ashtiani are connected. Their stories reflect different aspects of the same confrontation in Iran: the place of women – and how women who fall foul of the regime can be accused and charged with anything, with no guarantee of a fair trial.

While the existence of this faultline long predates the events surrounding the 2009 election and the rise of the Green Movement, what is true is that Iran's opposition, for a while at least, has amplified the calls for women's rights which have come to define both the international anxiety about and protest against Ahmadinejad's regime.

Dr Ziba Mir-Hosseini, a Cambridge-based activist and scholar, argues that the current thrusting of women to the fore of the struggle between "despotism and democracy", as she calls it, has been inevitable given the history of women's rights in Iran.

It is a tension, she argues, that has been exacerbated by the contradictory attitude of the 1979 Islamic revolution towards women's political rights. For while the family protection law, introduced by the shah to give women equal rights in issues such as divorce, was quickly revoked after his downfall, the Islamic revolution allowed women to continue voting – a political right, ironically, that was invested with more meaning after the revolution, even as women's human rights were being eroded again under the pretence of the revolution's "protection of women's honour".

The reformists also opened up political space for women to operate, according to Mir-Hosseini. "Mohammad Khatami, during the eight years of his reformist presidency, set up a Centre for Women's Participation that saw the number of women's NGOs in Iran increase from around 45 to over 500."

The consequence, she believes, was that feminism – a word that could not even be uttered in the early 1980s – and a feminism linked strongly to notions of wider human rights, took hold in a new generation of Iranian women.

But even during the period when the country's women were actively encouraged to participate, conservative elements of the regime were working to silence them.

With the birth of the One Million Signature campaign, set up by veteran women's rights activists in 2006, a year after the election of Ahmadinejad for the first time, the scene was set for a confrontation.

And while the campaign was successful in forcing the temporary shelving of Ahmadinejad's own new family protection law, which would have made polygamy easier for men and divorce more difficult for women, the emerging power of women activists, who became leaders of the street protests against the 2009 election result, set them on a collision course with the increasingly hardline regime.

"I think part of the reason there has been so much focus on women's rights since the election is the important role women had in the protests [in 2009]," says Maryam Namazie of the international support group Iran Solidarity. "They were at the very forefront, leading the chanting of the slogans. It is also a fact that women's rights are very much the target of this government."

If the face of that activism went largely unnoticed in the international media before the 2009 election protests, confined to the figure of Shirin Ebadi, the violent sweeping up of those protests catapulted a wider group of women to global attention, both as prisoners of conscience and campaigners on an international stage.

This was partly due to the Neda effect, which drew attention to the role of women activists after Neda Agha Soltan was gunned down, with her death, recorded on video and viewed around the world.

But if that event created a climate of intense interest in the often young women protesters, the response of the Ahmadinejad regime in clamping down on female campaigners drew even more attention.

A final component is the global attention paid to the stoning sentence delivered against Sakineh Mohammadi Ashtiani, which has served to underline what the women activists had long been saying about the broader attempt to dismantle women's rights.

Another prominent case is that of Shadi Sadr, who ran Rahai, a women's legal advice centre, campaigning against stoning and acted as defence lawyer for Nazar Ahari.

Arrested in July last year walking to Tehran University, where she had been planning to attend the Friday prayers led by the reformist former president Ayatollah Akbar Hashemi Rafsanjani, Shadi Sadr was bundled into an unmarked car and taken to Evin prison. Here she was held in solitary confinement and interrogated about other women's rights activists and the election, before being informed that she would be charged with endangering national security by causing riots.

In court, she was named as a leader of a women's rights movement accused of attempting to overthrow the Islamic republic. Shadi Sadr fled to Turkey two days later.

Describing her attempts to defend Nazar Ahari last week, Shadi Sadr said: "I was never given the permission to meet Shiva [Nazar Ahari] until the day I myself was arrested and, ironically, taken to the same cell Shiva was kept in until the day before I was taken in.

"On the wall of the cell she had written her stories and the charges she thought she was facing. Can you imagine that? The lawyer and her client both kept in one cell within a day? I was not allowed to meet her to hear what she had to say in her defence but that day I read it all on a cell wall.

"Shiva's arrest and especially charging her with muharebeh, which is punishable by death, is a clear message to all women's rights activists in Iran and the message is that they face execution if they continue."

The fate of Shadi Sadr, Shiva Nazar Ahari and Mahboubeh Abbasgholizadeh since 2009 is deeply instructive. Their cases, as the Iran Human Rights Documentation Centre (IHRDC) argued last month in a report entitled "Silencing the Women's Rights Movement in Iran", have been used to attempt to dismantle the women's rights movement, and to cow it into silence under the cover of national security concerns.

That has included claims of links with "terrorism", as in Nazar Ahari's case, or collaboration with foreign countries, which was the explicit claim made by the Iranian authorities last year when they identified the women's rights movement as being one of six groups behind an attempted "velvet revolution".

Whether the regime really believes that or not, the aim since then, says Parisa Kakaee, a veteran women's rights activist quoted in the IHRDC report, is to present women activists with three options: "to become inactive, to go to prison or to leave the country".

There is no indication that the campaign against women activists is letting up. Last month it was the turn of Nasrin Sotoudeh, 45, an outspoken lawyer and colleague of Shirin Ebadi who has defended a number of opposition activists and protesters. A member of the One Million Signatures campaign, she had been threatened by intelligence service officials that she would be arrested if she continued representing Shirin Ebadi, who left Iran a day before the election for a conference in Spain and didn't return for fear of harassment.

Ebadi said of Sotoudeh's arrest: "The only reason she was arrested is because of her human rights activities, because of defending her clients without any fear. Since the election last summer, a new move of intimidating and putting pressures on lawyers and especially women lawyers has emerged.

"Many have been forced to leave Iran and some are in jail. In this situation, Sotoudeh was one of the very few lawyers and women's rights activists who was still working in Iran."

Ebadi is certain why the present Iranian regime is so afraid of women. In an article in the Guardian, she declared: "Mark my words, it will be women who bring democracy to Iran."

That socially potent coincidence of women's rights and democratic reform is something Ahmadinejad and his supporters are determined should not be permitted to arise.

Iran's regime has also targeted foreign women in high-profile cases.



It had been hoped that US citizen Sarah Shourd would be releasedcorrect to mark the end of Ramadan, but she remains in custody. Shourd is one of three American hikers who crossed into Iran from Iraq's northern Kurdish region in July 2009.

Iran has threatened to put Shourd and her two male companions on trial for spying. Their families say they were hiking in the largely peaceful region of Iraq and that, if they did cross the border, it was accidental.

Clotilde Reiss, a French teaching assistant, was released earlier this year after being initially accused, like Shourd and her companions, of espionage. Reiss was arrested during the mass protests in 2009, when she was 24, and given two five-year jail sentences. Two Iranian men tried on the same day were hanged.

Found to have attended a demonstration and sent photographs of Iran to contacts at home, Reiss was put on trial with more than 100 others accused of trying to topple the regime and spent a month and a half in Evin prison before she was freed on bail and transferred to the French embassy.