In many ways they were typical 19-year-olds. One twin sister loved horses and animals, and worked in a local equestrian centre, while the other was into fashion and had a job in a shoe shop. Their lively faces, framed by long dark hair, were so strikingly similar, even their cousin had trouble telling them apart.

In almost any other country, the lives of these young women who loved dogs or designer trainers would be utterly ordinary.

Yet Taraneh and Romina Rahimi grew up in Iran and a little over a week ago Taraneh was sentenced to death by hanging, while Romina was given 25 years in prison.

Their crime? To be caught up in the protests that swept Iran on January 8 this year. The twins were arrested a week later and thrown into prison. Reportedly tortured and threatened with rape – Taraneh’s knee and fingers have been broken and both are missing clumps of hair – they learned their fate on August 31 in Branch 1 of the Revolutionary Court in the city of Isfahan in central Iran.

Taraneh, who turned 20 in prison, is one of ten alleged protesters to have been sentenced to death in the city. She is also the only woman.

‘They handpick the most beautiful, handsome, gorgeous kids – the brightest and the bravest – because they want to create an environment of fear in Iran,’ says their cousin Masoud Nourmohammadi.

‘If you rise up, this is what’s going to happen to you.’

Speaking exclusively to the Daily Mail, Masoud, 43, retells the events of January 8 and the horrifying news of the twins’ fate, as he’s been able to piece them together.

He is now based in Utah, in the US, where he works as a chief technology officer for a tech company – but he is still in close contact with the young women’s relatives in Iran. Indeed, the twins largely grew up with his own mother. ‘They’re like sisters to me,’ he says.

That Thursday of the protests, Taraneh had come to help Romina in the shoe shop in Shohada Square, a fashionable shopping district in Isfahan known for its shoes. Romina was an expert and would talk about brands she loved but couldn’t get in Iran.

The shop normally closed at midnight, not unusually late for a store in a big urban centre, but that day they finished early. Mass demonstrations against the Islamic Republic had begun in Tehran over a week before. Online, everyone was sharing a video post from Reza Pahlavi, the exiled son of the last Shah of Iran, encouraging people to protest.

Thousands responded in more than 200 cities. In Isfahan, they came from all directions – young children, mothers and grandparents – and crowded into the central square. At 8pm, Taraneh and Romina stood outside the shop among the protestors and joined in chants against the government: ‘Javid Shah’ (‘long live the King’).

The crackdown was swift and brutal.

On the streets, across the country, security forces used batons and firearms, targeting demonstrators from rooftops, bridges and building complexes. The mass killing continued over two nights. By mid-January, estimates of deaths ranged from 12,000 to 20,000, according to the UK government.

On January 8, Romina and Taraneh fled the crowds and went home to the apartment where they lived with their mother, a ten-minute walk from the square. They closed the front door and slid the bolt into place. At that moment they might have felt they’d escaped a dreadful fate.

A week later, however, in the middle of the night, masked men, later identified as being sent by the feared and powerful Islamic Revolutionary Guard Corps (IRGC), broke into the house where Taraneh was staying with a friend. They tied up her feet and hands, put a bag over her head and took her away. The next night, Romina was seized from her mother’s apartment.

It is a regime defined by its use of surveillance, says Masoud. ‘The Iranian government has a record of everybody. They use AI, cameras on the streets and their own agents on the ground.’

Taraneh was charged with ‘moharebeh’ (‘waging war against God’), while Romina – who had a stomach ache that night and dipped in and out of the protest – was accused of ‘aiding and abetting moharebeh’.

Seven months later, Masoud woke up to the news of Taraneh’s death sentence in a voicemail from a relative in Iran.

‘Knowing the girls were in prison was hard enough. Now this. The worst of news. It’s devastating,’ he says. ‘I’ve not been able to work, eat or sleep.’

His mother, a retired nurse, now lives with him, his wife and their three children – aged ten, 12 and 17 – in Utah. Her cries and sobs are so loud that he could hear them through the bedroom wall.

She was always very protective of her younger sister, the twins’ mother, he tells me. When his aunt fell pregnant and became a single mother, his mum looked after the girls while her sister worked as an accountant.

Masoud left Iran in 2005 to do a BA and then a master‘s degree in computer science in Utah, but before he went he sang songs to his aunt’s swollen belly. ‘I knew I wouldn’t be there to meet them, so I wanted them to at least hear my voice,’ he says.

Later he would talk with the twins, especially Taraneh, on the phone or via Facetime. ‘I live in an area of Salt Lake City where there are lots of horses and she’d often call me and ask to see the horses. She’d tell me the breed, their characteristics and how to train them. She knew so much.’

According to her lawyers, Taraneh has 18 days to appeal her death sentence, but in many cases in recent months the Islamic Republic has ignored the law, says Masoud. ‘They just sentence and take the kids and execute them.’

His mind constantly circles with thoughts of his cousins’ suffering.

Taraneh’s execution could be ‘tomorrow, or the day after, at the light of day, because that is the most dangerous time for prisoners on death row’. Most, he says, are hanged at sunrise, usually within the prison walls, as the dawn call to prayer is broadcast. The news is then announced on media affiliated with the Islamic Republic.

‘They are in hell,’ he says.

Masoud feels powerless to do anything other than ‘be their voice’ – but at the same time knows he is risking the lives of family members still in Iran by speaking out.

‘I got a text message a couple of days ago. “We know where your family lives, here’s their phone number, don’t talk to anyone because we can take them and kill them.”’

But the world, he says, needs to know ‘what is happening in Iran’.

Executions have surged inside the country this year, human rights groups report, with the US war against Iran only serving to embolden the regime.

With international attention focused on oil prices and shipping lanes, the Iranian authorities have sentenced dozens of January protestors to death. According to Human Rights Watch and the Washington-based Abdorrahman Boroumand Center for Human Rights in Iran, at least 56 people have been executed on explicitly political or ‘national security’ charges – including ‘spying’ and ‘collaboration with hostile states’ – from January to July this year.

In Isfahan, two male protestors, both in their twenties, were executed in Alikhani Square on July 28. As the dawn call to prayer was broadcast across the city, they were hanged in public from yellow cranes. A third detainee did not reach the gallows that morning but instead, according to human rights groups, suffered a heart attack while being kept in a van for eight hours before the execution. Subsequently revived at a hospital, the man was returned to prison two days later and now faces imminent execution for the second time, activists have said.

Two others charged in the same case were hanged on July 19, and at least eight more may be executed, including an 18-year-old boy named Shervin Bagherian.

‘What is striking today is the speed with which death sentences are being imposed, the return of public executions and the use of broadly defined espionage charges to silence witnesses and deter the circulation of information,’ according to Roya Boroumand, the Abdorrahman Boroumand Center’s executive director.

She said the public hangings are intended to reassure regime supporters that the Islamic Republic is still very much in control. ‘It’s a show for their own constituency.’

Meanwhile, the Iranian people feel as though the regime is waging war on them. When the twins were seized by the IRGC in January, their mother and relatives searched for them for four-and-a-half months, repeatedly phoning hospitals.

Eventually, their mother had a call from the authorities. ‘They’re in Dowlatabad,’ a voice said, referring to the women’s prison in Isfahan.

In the middle of May, she visited them. They were unrecognisable – their faces red and swollen, their scalps showing where clumps of hair had been yanked out.

Masoud now believes the IRGC exploited the closeness of the sisters’ bond as twins. ‘They used Romina to put pressure on Taraneh.’ Indeed he learned Taraneh signed a ‘confession’ only when IRGC guards threatened to rape her sister in front of her.

‘Taraneh had to have surgery on her left knee a couple of years ago after an incident with a horse. They broke that knee again in prison. They broke her fingers,’ says Masoud, ‘She reached out to the clinical team in prison. “My knee is broken,” she said, “You need to help me.”

‘“You’re going to die anyway,” came the response, we have heard. “What does it matter if you’re a cripple or not.”’

Masoud tells me Taraneh could hear her sister screaming as she was tortured in the next cell. ‘They said, “sign this confession or we’ll rape Romina in front of you.”’ Taraneh signed.

He tells me what the girls are like. Yes, they are identical but of course there are differences too. Taraneh was gentle, empathetic, a ‘people and animal lover’ who’d go nuts at the sight of Nova, his English golden retriever, on FaceTime.

Romina meanwhile was defiant, independent. ‘A classic example of Iran’s Gen Z,’ says Masoud, by which he means the younger generation who have been exposed to social media and western influences.

‘When she was around 15, she asked me to get her a Nike jacket. “Surprise me,” she said. ‘It was the only thing she ever asked me to do.’ He bought two identical jackets – one for each teen.

Aged 17, Romina got a small tattoo of a map of Iran on the back of her neck: a popular symbol for her generation. ‘They’re proud of being Iranian, proud of their history and culture,’ says Masoud.

As far as the regime is concerned, Iran’s history starts in 1979 when the country stopped being a monarchy and became the Islamic republic under Ayatollah Ruhollah Khomeini. But younger people look further back to the country’s ancient Persian heritage. ‘They want freedom, a secular democracy.’

And yet Masoud is baffled by their arrest, let alone the charges. Neither were politically active. ‘They were the last people in my family I’d have guessed would go out [to the protests].’

Indeed most of the 16 defendants in the Isfahan Shohada Square case were not prominent political activists but business owners, shopkeepers or employees of shoe shops near the square. Across Iran many thousands of people have been detained at the hands of the regime’s ruthless security forces, say human rights groups.

One news agency recorded 42,324 arrests, 261 cases of forced confessions being broadcast on state media and 11,026 people being summoned to security institutions.

Unsurprisingly, Iran Human Rights Monitor says the opaque proceedings of the Isfahan Shohada Square case also violate fair trial standards. For example, the court session to hear the charges was not open and public but held in a prison while defence lawyers were denied access to case files. ‘They only had ten minutes to read through thousands of pages on the day of the trial,’ says Masoud.

It is widely believed that confessions have been extracted by torture. Amnesty International has called for ‘UN member states to take urgent coordinated diplomatic action to press the Iranian authorities to halt further executions’.

Taraneh’s dream was to open an equestrian centre; Romina’s to design sustainable trainers made from recycled materials. Neither of them were committed activists, says Masoud. Like many young people, he says they got caught up in the mood of optimism that night – but were then picked up and used as a brutal example to others.

Masoud wishes he’d been in Iran that night. ‘I would have gone to the square, brought them home and locked them down. Kept them inside the house.’ His aunt tried. ‘But it was impossible to stop them.’

Their minds were in another place, focused on freedom and hope. It’s the injustice of it all that breaks Masoud.

‘They were just two young girls chanting in the streets.’