In letters smuggled out of her cell in Evin prison and seen by both The Times and The Guardian, Cambridge-educated Kylie Moore-Gilbert begged to be allowed to leave the restrictive unit where she has served periods in solitary confinement.
Dr Moore-Gilbert, who most recently worked as a lecturer in Islamic studies at the University of Melbourne, was arrested in September 2018 while at an educational conference and later convicted of espionage.
She is understood to be serving a 10-year sentence, but has described being shown two conflicting sentences, one outlining 13 months' imprisonment and the other a decade-long term.
Ten letters, written in crude Farsi, were sneaked out of the prison.
The letters are variously addressed to three men. One, named Mr Vasiri, is thought to be a deputy prosecutor in the Iranian judiciary, while Mr Ghaderi and Mr Hosseini are thought to be mid-ranking officers in the Islamic Revolutionary Guard Corps (IRGC).
In the letters, Dr Moore-Gilbert referred to meetings with these men, who appear to have influenced her treatment in prison, including being allowed access to books.
The prison section she is being held in is reportedly run by the IRGC, while her case is managed by the judiciary.
Dr Moore-Gilbert detailed the conditions she has endured while incarcerated.
In a letter written last July she said: "I'm taking psychiatric medications, but these 10 months that I have spent here have gravely damaged my mental health.
"I am still denied phone calls and visitations, and I am afraid that my mental and emotional state may further deteriorate if I remain in this extremely restrictive detention ward."
In a letter sent to her Iranian case manager, Dr Moore-Gilbert stated her "official and definitive rejection of your offer to me to work with the intelligence branch of IRGC".
"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."
Dr Moore-Gilbert also used the letters to protest her innocence, saying she had been the victim of "fabrications and trumped-up accusations".
On September 18 she wrote about having food allergies. "I cannot eat most of the food coming out of Ward 2A's kitchen ... I am entirely alone in Iran. I have no friends or family here and in addition to all the pain I have endured here I feel like I am abandoned and forgotten."
Other Britons imprisoned in Evin include Nazanin Zaghari-Ratcliffe and Anoosheh Ashoori who are serving five and 10 year sentences respectively on charges disputed by the British Government.
The Australian government secured the release of British-Australian Jolie King and her Australian boyfriend Mark Firkin last October, three months after they were arrested in Iran.
Dr Moore-Gilbert recently smuggled another letter from the prison in which she begged Australian Prime Minister Scott Morrison to secure her freedom.
Australian Foreign Minister Marise Payne spoke with her Iranian counterpart Mohammad Javad Zarif about the situation on the sidelines of a conference in India on January 16.
A week earlier, Prime Minister Boris Johnson raised concerns about British dual nationals with Iran's President Hassan Rouhani.