PERTH, Australia (AP) — Australia's attorney general has refused to comment whether a prisoner swap was behind the release of two Australians from Iran in exchange for an Iranian student who was facing extradition to the United States.

The couple, Jolie King and Mark Firkin, returned to Australia on Saturday after all charges against them were dropped. They were arrested for flying a drone near a military zone without a license.

At the same time, Iran's state TV reported that an Iranian scientist held for 13 months in Australia for purchasing a defense system ffom the U.S. had returned home.

Attorney General Christian Porter confirmed that Dehbashi would not be extradited to the United States but refused to comment on an apparent swap.