Iran has temporarily freed 70,000 prisoners from jails around the country out of fear coronavirus could spread through prisons unchecked, but British-Australian academic Kylie Moore-Gilbert has not been released.

Political prisoners have overwhelmingly been excluded from the furloughing of prisoners, with other dual nationals such as Nazanin Zaghari-Ratcliffe, an Iranian-born British aid worker, remaining imprisoned despite growing concerns for their health.

“A number of dual and foreign nationals are at real risk. If they have not ... got [coronavirus] they are really fearful of the conditions,” Javaid Rehman, the UN’s special rapporteur on the situation of human rights in the Islamic Republic of Iran, said.

“This is also my worrying concern and therefore I have recommended to the state of the Islamic Republic of Iran to release all prisoners on temporary release.”

The Australian government spoke to a UN human rights committee session dedicated to the human rights situation in Iran, also calling on Iran to release all political prisoners.

But Australia’s representative did not mention Moore-Gilbert by name, in keeping with Australia’s espoused strategy of quiet diplomacy rather than public pressure on the Iranian regime.

Moore-Gilbert, a University of Melbourne professor, has been held in the Revolutionary Guards-run Ward 2A of Evin prison in Tehran for 18 months, having been sentenced in a secret trial to 10 years in prison for espionage, a charge she denies.

In letters smuggled from prison Moore-Gilbert has revealed she has been held for months in solitary confinement, does not have enough food or medicine, or money to buy personal items. “I feel like I am abandoned and forgotten … I am an innocent victim.”

She said she rejected an offer from Tehran to spy for the Iranian government that would have seen her freed.

“I am not a spy. I have never been a spy and I have no interest to work for a spying organisation in any country. When I leave Iran, I want to be a free woman and live a free life, not under the shadow of extortion and threats.”

Moore-Gilbert was arrested in September 2018 after having attended an academic conference at which she was invited to speak in Qom. Fellow conference delegates, and an interview subject for her academic work, flagged her as “suspicious” to the Revolutionary Guards, who arrested her at Tehran airport. No evidence has ever been presented publicly that Moore-Gilbert was involved in espionage, and the Australian government says it rejects her conviction.

Iran has reported 881 new coronavirus infections and 54 new deaths within the past 24 hours, taking the total number of coronavirus cases in the country to 8,042, with 291 deaths, according to a health ministry spokesman.

Judiciary chief Ebrahim Raisi announced a further furloughing of prisoners as authorities seek to counter one of the worst national outbreaks outside of China, where the new virus originated, and one of the highest death rates from the illness.

Raisi said the release of prisoners would continue “to the point where it doesn’t create insecurity in society”, according to the Mizan news agency. There were no details offered on when those released would be forced to return to jail.

There is widespread concern for the health of prisoners inside Iran’s arcane, under-resourced and overcrowded prison system.

The Center for Human Rights in Iran, speaking with sources inside prisons, say at least eight prisoners have contracted coronavirus, including five in Evin prison in Tehran, where Moore-Gilbert is held.

Wards in Evin prison have run out of medicines, sanitary and hygiene supplies, according to relatives of dual nationals held in the prison.

“We’re receiving disturbing reports that Iranian authorities are neglecting their domestic and international legal obligations to protect prisoners from contracting Covid-19 during this health crisis,” centre for human rights in Iran executive director, Hadi Ghaemi, said.

“Prison populations are more susceptible to viral outbreaks than the general population because of their confined living conditions,” he added. “Iranian authorities should ensure the safety and wellbeing of all prisoners and exhaust all means of protecting this vulnerable population.”

Rehman, the UN’s rapporteur on Iran, said sanctions on the country had contributed to serious shortages of medication and medical equipment, including in prisons.

“Overcrowding, poor nutrition and a lack of hygiene are also serious concerns. These issues indicate a high risk to prisoners’ health from malnutrition and disease.”

In Geneva this week, Australia’s representative to the UN in Geneva Sally Mansfield told the special rapporteur on the situation of human rights in the Islamic Republic of Iran that Australia was “deeply concerned” about the deteriorating situation inside Iran.

Mansfield said Australia called on Iran to “ensure fair trials and due process … and release political prisoners”. But she did not mention Moore-Gilbert, whose detention, trial and conviction was not mentioned publicly by the Australian government for nearly a year.

Government backbencher Dave Sharma, the member for Wentworth and a former Australian ambassador, said Moore-Gilbert should be released out of concerns for her health.

“Her health has not been good to begin with ... she’s been held in a prison ... where there have been reports of a coronavirus outbreak and Iran is one of the countries worst hit by this coronavirus,” Sharma said.

“I would encourage the government of Iran to consider releasing Kylie Moore-Gilbert in that context.”

Academics have supported Moore-Gilbert and condemned the conditions under which she is being held. The Australia Association of University Professors has raised concerns that Moore-Gilbert has had minimal consular access during her imprisonment.

“Through letters smuggled out of the notorious Evin prison, she complains of extreme psychological stress and a sense of emotional isolation. This is utterly unacceptable. Academics should be free to pursue their research interests without fear of persecution and imprisonment.”

The association suggested Australia’s pursuit of quiet diplomacy has not yielded any appreciable freedoms.

“While we acknowledge that the Department of Foreign Affairs and Trade has tried to secure Dr Moore-Gilbert’s release, she is still in prison. We call upon the Australian government and prime minister Scott Morrison to treat this matter with the utmost urgency to secure her immediate release.”

The foreign affairs minister, Marise Payne, has maintained “the government has been working extremely hard in relation to the ongoing detention of Kylie Moore-Gilbert”.

“We don’t accept the charges on which she has been held and are concerned for her protection and the conditions under which she is held.”

A department spokesman said: “We continue to believe that the best way to secure a successful outcome is through diplomatic channels and not through the media.”