The lawyer of an Iranian academic wanted in the United States has rejected the idea Tehran used “hostage diplomacy” to secure a prisoner swap deal for his client's release.
Iranian state TV aired footage of Reza Dehbashi Kivi’s emotional return to Tehran on Saturday, after being held for 13 months in a Queensland prison.
The timing of his arrival prompted speculation a prisoner swap deal had taken place in exchange for Tehran's release of a Perth couple just hours earlier.
Mr Dehbashi Kivi had faced extradition to the United States, over conspiracy crimes allegedly committed in Tehran, attempting to circumvent US sanctions. 
The Iranian academic’s lawyer Pouyan Afshar said he was not aware of any special deals between Canberra and Tehran.
Travel bloggers Jolie King and Mark Firkin. Source: Instagram
“I don’t know if it was [a prisoner swap deal],” he told ABC Radio on Monday.
“[But] my view is that there is some connection.”
“The essence of it was that that there were always discussions throughout the process,” he said.
“Certainly at a consular level as I understand it.”
Perth couple Mark Firkin and Jolie King are back in Australia with all the charges against them dropped, after being arrested for flying an unlicensed drone near a military zone.
The couple had been globetrotting for two years and documenting their travels on Instagram and YouTube.
Attorney-General Christian Porter has not linked their release to the decision not to extradite Mr Dehbashi Kivi to the United States.
Reza Dehbashi Kivi returns home to Tehran after 13-months in custody in Australia. Source: @iribnews
"The Australian Government does not comment on the details behind its consideration of particular cases,” he said on Saturday.
“While it is likely that because of Mr Kivi’s nationality some will speculate regarding this matter, consistent with prior practice I do not intend to comment further on the particular details of this case.”
Mr Dehbashi Kivi was working as a research student at the University of Queensland before being arrested in Brisbane in September last year.
Iranian academic Reza Dehbashi Kivi after arriving back in Tehran. Source: @iribnews
He faced six charges being brought by US authorities, including conspiring to export special amplifiers banned under United States sanctions.
The 38-year old was accused of sending American equipment used for detecting stealth planes or missiles to Iran.
Mr Afshar said the charges against his client were based on offences allegedly committed ten years before he was taken into custody.
“This was many years before he ever decided to come to Australia to conduct his research.”
“[But] even on its face, this man ought not to have been extradited to the United States, given the laughable amount of evidence,” he said.
At the University of Queensland, Mr Dehbashi Kivi had been working developing a machine to detect skin cancers.
He had raised concerns he couldn't get a fair trial in the United States due to prejudice towards Iranians.
Foreign Minister Marise Payne held several meetings with her Iranian counterpart Javad Zarif calling for the release of three Australians being detained in Tehran.
A third Australian still in detention, Melbourne University lecturer Kylie Moore-Gilbert, has been held since October last year, and is facing 10-years in prison for spying.
Mr Afshar rejected the premise Iran is engaging in “hostage diplomacy”, to secure the release of prisoners.
Dr Kylie Moore-Gilbert remains behind bars in Iran. Source: Supplied
“I don’t accept that Iran engages in hostage diplomacy,” the lawyer said.
“I don’t think that there are people who go and snatch people off the street simply to engage in a trade.”
