An Australian-British academic released after two years imprisoned in Iran on spying charges said she thanked supporters from the "bottom of my heart" Tuesday, saying they helped her through a "never-ending, unrelenting nightmare."

In her first statement since arriving back in Australia, Middle East scholar Kylie Moore-Gilbert said she was "totally blown away" by efforts from friends and family to secure her release.

"I honestly have no words to express the depth of my gratitude and how touched I am," the 33-year-old said.

"It gave me so much hope and strength to endure what had seemed like a never-ending, unrelenting nightmare. My freedom truly is your victory. From the bottom of my heart, thank you!"

Moore-Gilbert was released last week in a swap for three Iranians linked to a botched plot to kill Israeli officials in Bangkok.

She was arrested by Iran's hardline Islamic Revolutionary Guard Corps in 2018, after attending an academic conference in the holy city of Qom in central Iran.

She was later charged with espionage and sentenced to 10 years in jail, allegations she has denied.