Friends of a British-Australian academic jailed in Iran on spying charges launched a public campaign to win her freedom Thursday, saying that Australia's strategy of quiet diplomacy had failed.

Nearly two years after Kylie Moore-Gilbert was detained while trying to leave Iran, a group of friends and colleagues are demanding that Canberra do more to resolve the situation.

The "Free Kylie" group said it had respected the Australian foreign ministry's guidance to "remain quiet" and allow diplomats to do their work.

"But we believe that this strategy on its own has failed," they said, adding the policy had made "little headway in improving her day-to-day living conditions, let alone securing her release".

Moore-Gilbert, a lecturer in Islamic Studies at the University of Melbourne, is serving a 10-year sentence for spying, a charge she has strenuously denied.

This week she was moved from a jail in Tehran to a notorious women's prison in an old chicken-processing factory outside the capital.

Blacklisted under US human rights sanctions, Qarchak prison has become a byword for the ill-treatment of political prisoners and is described as filthy and coronavirus-ridden by non-governmental groups.

"The quarantine unit... holds all kinds of criminals, including those convicted of murder and drug and financial offences," said the US-based Center for Human Rights in Iran.

Moore-Gilbert was reportedly arrested at Tehran airport by Iran's hardline Islamic Revolutionary Guards Corps in September 2018 after attending a conference in Qoms.

It is believed she was reported by a conference delegate or someone interviewed for her research, which focused on the Gulf -- in particular Bahrain, a crucible for competition between Iran and Saudi Arabia.

Australia says the case of Kylie Moore-Gilbert, an academic jailed in Iran, is one of its 'highest priorities'
Australia says the case of Kylie Moore-Gilbert, an academic jailed in Iran, is one of its 'highest priorities' AFP / ATTA KENARE

"Please, I beg of you to do whatever it takes to get me out," Moore-Gilbert wrote in a June 2019 letter to Australia's Prime Minister Scott Morrison.

The Cambridge graduate said in a separate letter that she had been on hunger strike five times, while unconfirmed reports said she had attempted suicide.

Australia's foreign ministry this week said her case remained one of its "highest priorities, including for our embassy officials in Tehran".

In an unusually strongly-worded statement, the department also warned it would "hold Iran responsible for Dr Moore-Gilbert's safety and well-being".

Prisoner and hostage negotiations are notoriously fraught, with governments and families forced to decide if quiet discussions are less likely to antagonise captors, often against a fraught geopolitical backdrop.

Iran's complex political and judicial system -- which sees hardliners, reformists and myriad state institutions vying for influence -- can make things more complex still.

"Even though the situation is sensitive, there are avenues Australia can pursue on behalf of Kylie," said her friend and colleague Jessie Moritiz, suggesting the US may be able to help facilitate a prisoner swap.

Relations between Washington and Tehran have gone from bad to worse under President Donald Trump, who pulled out of a landmark deal that saw Iran restrict its nuclear programme -- long suspected of being cover for developing a weapon -- in return for international sanctions relief.

More recently, Iran vowed reprisals for the US assassination of Qasem Soleimani, who masterminded paramilitary operations in Iraq, Syria and Lebanon.

Nonetheless, the "Free Kylie" group said the government should explore every option and urged Australians to petition members of parliament and the media to raise awareness.