Former foreign minister Julie Bishop has offered to assist with negotiations over the Australian citizens detained in Iran.

The Morrison government is lobbying for the release of two Perth travel bloggers and a Melbourne university lecturer being held in Tehran’s notorious Evin prison.

“I have a longstanding and constructive relationship with Iranian Foreign Minister (Javad) Zarif and I met with President (Hassan) Rouhani during my visit to Tehran,” Ms Bishop told the Nine newspapers on Monday.

“I am available to support the government in its efforts to secure the release of the detained Australians, should the government make that request.”

University of Melbourne academic Kylie Moore-Gilbert has been imprisoned in Iran since October 2018.

Dr Kylie Moore-Gilbert has been sentenced to 10 years in jail and has received only limited consular visits.

In a separate incident, Perth couple Mark Firkin and Jolie King were detained by Iranian authorities about 10 weeks ago.

They are accused of flying a drone near a restricted military zone in Tehran.

Foreign Minister Marise Payne has raised the imprisonment of the three Australians with her Iranian counterpart several times, as diplomats continue to work behind the scenes to try and secure their release.

-AAP