Iranian Australians who spoke with the ABC said threats and intimidation were common when campaigning for change in Iran. (ABC News: Jacintha Santoso)

By Emily Baker, ABC News

Iranian political activist Borna Kazerani says he was lashed, imprisoned and raped by authorities in his home country, sparking his move to Australia about two decades ago.

But even he has been shocked by the sheer brutality of the Islamic regime in its response to protests that first broke out in December.

In January, in the brief moments Iranians could access the internet during a communications blackout, Mr Kazerani's phone lit up with confronting videos from his homeland — including the corpses of people slaughtered during street demonstrations.

The filmmaker said he identified three friends among the dead. Another three have been killed — he said those women's bodies had not yet been found — and his grandfather also died, likely waiting for unrelated medical attention from help that never came.

Mr Kazerani does not know exactly what happened to his loved ones because he is unable to speak freely with his family or friends for fear their communications are monitored.

"We're done, enough is enough,"  Mr Kazerani said. "That's why we're standing up for the revolution."

In the midst of this grief and trauma, Mr Kazerani said he feared for his life — even in Australia.

He has received abuse and threats from hardline supporters of both the current regime and the man considered by some as a future leader, exiled prince Reza Pahlavi.

Mr Kazerani has been critical of both sides in his campaign, instead wanting a fresh start for Iran.

"Choke on blood and die," said part of one Instagram message translated from Farsi to English, seen by the ABC, in which the sender spoke in support of Mr Pahlavi.

Mr Kazerani shared another message containing a death threat, and one other in which an individual threatened sexual assault.

"I've stopped participating and going to the rallies or demonstrations because they know my face," Mr Kazerani said.

Iranian Australians who spoke with the ABC said threats and intimidation were common when campaigning for change in Iran, highlighting the risks the diaspora takes in speaking out — even from Australia.

The Australian government and domestic spy agency ASIO have sounded the alarm on Iranian authorities' interference in Australia in recent years, including intimidation of Iranian Australian activists and alleged attacks on Jewish community sites.

In response to the antisemitic attacks, Australia expelled Iran's ambassador, Ahmad Sadeghi and declared the country's security apparatus, the Islamic Revolutionary Guard Corps, a terrorist organisation.

Iranian diaspora 'very fearful'

Artist Shahrzad Orang creates digital artwork from her home in Sydney in solidarity with Iran's political prisoners and protesters.

She shared with the ABC messages in which a person in Iran — who suggested they were connected with the regime — last year threatened her with execution.

"I'm going to make such a nightmare that you'll want to kill yourself," the message, translated from Farsi to English, also read.

A separate series of messages from another individual contained insults and sexual threats.

"This is what we are dealing with," Ms Orang said.

Advocate Sarah Bolouri said the diaspora also feared for the safety of their loved ones abroad when speaking out.

"The Iranian diaspora is very fearful of speaking to the media, they're very fearful when they're going to protests, they're very fearful even to post on social media, because the repercussions are for our family," she said.

"The repercussions are also intimidation here. There's surveillance that happens in Australia as well."

A Department of Home Affairs spokesperson said the Australian government "does not tolerate surveillance, harassment, or threats towards any Australian citizens or individuals lawfully in Australia."

But, Ms Bolouri said, staying silent was no longer an option.

"We've got nothing to lose," she said.

December protests centred on Iran's cost of living crisis soon snowballed into nationwide street demonstrations calling for the end of clerical rule.

The country has been an Islamic theocracy overseen by a powerful Supreme Leader since the overthrow of the monarchy in 1979.

US-based Human Rights Activists News Agency has estimated more than 7,000 people have been killed by the regime in response to the protests — including 226 children — and more than 53,000 people arrested.

The death toll is likely higher; a group of doctors in Iran has reported that the death toll could exceed 30,000, though this has not been verified.

Human rights organisation Amnesty International has described the Iranian regime's actions as a "massacre" and "the deadliest period of repression by the Iranian authorities in decades of Amnesty's research".

"The scale of bloodshed is beyond imagination," Ms Orang told the ABC >>>