An Australian academic being held in an Iranian prison has begun a hunger strike, along with another academic.

Key points: Kylie Moore-Gilbert and French-Iranian researcher Fariba Adelkhah have been refusing food and water

Kylie Moore-Gilbert and French-Iranian researcher Fariba Adelkhah have been refusing food and water Dr Moore-Gilbert is serving a 10-year sentence for spying, a conviction Australia does not accept

Dr Moore-Gilbert is serving a 10-year sentence for spying, a conviction Australia does not accept The Government has said it is doing "everything we can" to bring the Melbourne University academic home

Melbourne University lecturer Kylie Moore-Gilbert has been held in the notorious Evin prison in Tehran since October 2018.

She was convicted of spying and sentenced to 10 years' jail.

A recent appeal failed.

A letter dated Christmas Eve and published by supporters of Dr Gilbert-Moore and French-Iranian researcher Fariba Adelkhah, also accused of spying and detained in Iran some months ago, says the women have begun refusing food and water.

France's Sciences Po school (CERI), where Ms Adelkhah works as a senior research fellow, confirmed it in a tweet, Reuters reports.

"CERI confirms the hunger strike begun by Fariba Adelkhah and her co-detainee Kylie Moore-Gilbert," the institute said on Wednesday.

Kylie Moore-Gilbert is serving a 10-year sentence after an appeal failed. ( Supplied: Department of Foreign Affairs and Trade )

The prison has a reputation for brutal treatment of inmates, including mock executions, beatings and psychological "torture".

The Federal Government has previously described Dr Moore-Gilbert's situation as complex, and Foreign Minister Marise Payne has said Australia does not accept the spying charges against her.

"She's been receiving consular assistance and had a visit recently," Prime Minister Scott Morrison said on Tuesday.

"We're doing everything that we can do bring her home."

Mr Morrison said the Government remained concerned for Dr Moore-Gilbert's welfare.

Dr Moore-Gilbert is a Middle East expert at the University of Melbourne's Asia Institute, specialising in the Arab Gulf states. She has also studied at Cambridge.

Her family has not spoken publicly but earlier this year released a statement via the Department of Foreign Affairs and Trade (DFAT).

"We believe that the best chance of securing Kylie's safe return is through diplomatic channels," the statement said.

In October, Australian bloggers Jolie King and Mark Firkin were released from the prison after several months of detention for reportedly flying a drone without a permit.

Jolie King and Mark Firkin were also held at Tehran's Evin prison. ( Instagram: Jolie King )

Hours after their release, the Australian Government revealed that an Iranian scientist who had been studying in Brisbane would not be extradited to the United States.

Attorney-General Christian Porter would not say if the two cases were linked, only that "extradition requests are considered on a case-by-case basis".

However, Iran has detained dual Iranian nationals and those with Western ties in the past, to be used as bargaining chips in negotiations.

AAP/ABC