"We live in an uncertain world and we live in a world where there are regimes that don't act in relation to people's liberties and rights and with the freedoms that we enjoy here in Australia,"he said."That is just a sad reality of the world which we live in and Australia has to deal in that world."

Foreign Minister Marise Payne also would not be publicly drawn on details of how the deal was struck.

"I'm not going to comment on diplomatic discussions with other governments,"she said.

She said the government was not shifting its stance on Iran in light of the academic's release.

"We have consistently rejected the grounds on which the government of Iran arrested and detained Dr Moore-Gilbert and we continue to do so,"she said.

Senator Payne said Dr Moore-Gilbert was"healthy and in good spirits"and would go into two-week mandatory quarantine when she arrived in Australia.

[We've had] a few false starts on this in the past but we have got there now.

PM Scott Morrison

"I am not able to disclose the location of her quarantine nor any other private details. We would all understand that Dr Moore-Gilbert has adjustments to make,some plans to consider,so this will be a period of privacy and one expects,decompression,"she said.

She also warned Australians against any travel to Iran,warning of the risk of arbitrary arrests.

"We advise do not travel to Iran and particularly at this point in time due to the COVID-19 outbreak that is common across our formal travel advice,but we also add that the security situation remains volatile and there is a high risk that you could be arbitrarily detained or arrested."

Dr Moore-Gilbert paid tribute to the Australian diplomats who worked to secure her release and thanked the"warm-hearted,generous and brave"Iranian people and"the great nation of Iran".

Her family said they were"ecstatic"over the news,which comes after she spent more than 800 days in custody,lauding Mr Morrison,the ambassador to Iran and Senator Payne.