Reza Dehbashi, a student of the University of Queensland, had been arrested for attempting to purchase and transfer advanced American military radar equipment via Dubai to Iran.
Since his arrest in August 2018, The 39-year-old Ph.D. student had been fighting to avoid extradition to the US, after American authorities accused him of exporting military equipment for detecting stealth planes or missiles to Iran.
Dehbashi had been working on a "skin cancer detection device" at the time of his arrest. He had dismissed the charges as "a misunderstanding" and "unfair".
State television has shown footage of what it said was Dehbashi arriving at Tehran's Imam Khomeini International Airport.
MNA/IRN83503794