US-born Saberi, who had been living in Iran for six years and working as a reporter for Western media outlets while writing a book, told National Public Radio (NPR) that no one saw her being taken from her home on January 31 by four men from the Iranian intelligence ministry, and she wasn't allowed to contact friends or family when she was thrown in Evin the same day.
"After I realized that nobody knew where I was, I was very afraid, and my interrogators threatened me and said, if you don't confess to being a US spy, you could be here for 10 years or 20 years. You could even face execution," she told NPR.
"And I thought, well, if something happens to me, my family doesn't know where I am, maybe they would never find out. And so I made a false confession and I said, 'Yes, I'm a US spy,'" the 32-year-old told NPR's Melissa Block, host of the popular "All Things Considered" program.
"I'm still not sure what they arrested me for. It wasn't for buying alcohol; it wasn't for reporting without a press pass," Saberi said.
Both accusations have been raised by the media and officials in Iran as the reason for Saberi's arrest.
Saberi told NPR that her interrogators had from the go accused her of spying for the United States.
"However much I told them that I was not — that I was simply writing a book and doing interviews for a book, which I hoped to use to show English speakers around the world a more balanced and complete picture of Iranian society — however much I told them this, they told me I was lying and that I was a US spy," she said.
In Evin, the jail in the Tehran suburbs where many political prisoners are held, Saberi endured "severe psychological and mental pressure, although I was not physically tortured.
"The first few days, I was interrogated for several hours, from morning until evening, blindfolded, facing a wall, by up to four men, and threatened … I was in solitary confinement for several days," Saberi said.
Those days in isolation, when nobody knew where she was, were the "most difficult time for me," said Saberi.
"I prayed a lot — I prayed more than I ever have in my whole life."
After several weeks, Saberi was put in a cell with "other political prisoners," she said.
She drew strength from her fellow inmates, whom she described as "some of the most admirable women I've met, not only in Iran, but all over the world.
"They're not willing to give in to pressure to make false confessions or to sign off to commitments not to take part in their activities once they're released; they would rather stay in prison and stand up for those principles that they believe in," Saberi said.
"Many of them are still there today," she said.
Saberi eventually recanted her confession of spying. She walked free from Evin jail on May 11 after a court reduced her eight-year prison term for espionage to a two-year suspended sentence.
She arrived back in the United States last week, telling reporters who met her at Dulles Airport near Washington that she sang the US national anthem to herself while in Evin prison.
Asked if she had any plans to return to Iran, Saberi replied, "Definitely."
She had "learned to love the country" during her six years there.
"Most of the people were so hospitable to me — so kind and so generous.
"Definitely, I hope to go back someday," she said.
