University of Queensland research student Reza Dehbashi Kivi has arrived home in Iran after avoiding being extradited to the United States.

Key points: The 38 year old had been in custody since September last year

The 38 year old had been in custody since September last year Iranian state TV says he has returned home to Iran

Iranian state TV says he has returned home to Iran The Government did not say whether the case is linked to two Australians being released after being detained in Iran

Iranian state TV aired footage of, Mr Dehbashi Kivi returning home after 13 months in custody in Australia after he allegedly circumvented the US sanctions against his native Iran.

Footage shows Mr Dehbashi Kivi wiping tears from his eyes as he walked into Tehran's Imam Khomeni international airport.

The 38-year-old was accused of exporting American equipment for detecting stealth planes or missiles to Iran.

It comes on the same day that two Australians were released after being detained in Iran for more than three months.

But Attorney-General Christian Porter did not say the two cases were linked.

"The Australian Government does not comment on the details behind its consideration of particular cases," he said in a statement.

"And while it is likely that because of Mr Dehbashi 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, particularly when any such response from me may diminish our Government's capacity to deal with future matters of this type in Australia's best interests."

Mr Dehbashi Kivi was arrested in Brisbane and taken into custody in September last year, while he was living in Redbank Plains.

He failed in an effort to be released on bail as US officials sought to extradite him on six charges, including conspiring to export special amplifiers classified as "defence articles" under the US munitions list.

The US Government had alleged the amplifiers were bought from American companies.

Another charge accused him of "aiding and abetting in the exportation of defence articles from the United States to Iran".

Mr Dehbashi faced a maximum of 20 years in prison for the alleged offences, which dated back to 2008, when he was living in Iran.

During his bail hearing last year, his lawyer told Brisbane Magistrates Court he was studying his PhD at UQ, which involved working on developing a machine to detect skin cancers.