Harper Lee's 'To Kill a Mockingbird' Touched US Reporter Jason Rezaian During His Iran Trial

Jason Rezaian was among Americans just released by Iran in a prisoner swap.

Rezaian was one of a few U.S. citizens freed by Iran as part of a prisoner swap last month after he was accused by Iranians of being a spy and spent 18 months imprisoned.

Rezaian, 39, told Washington Post editors last month about some of his experiences in prison, saying at one point he spent 49 days in solitary confinement, the Washington Post reported. Rezaian said he was later placed in a 15-by-20-foot room with three cots and no mattresses, according to the Post.

Publishing house HarperCollins released a statement today confirming that Lee, the iconic "To Kill a Mockingbird" author, "died peacefully" early this morning at age 89.

Lee was represented by HarperCollins agent Andrew Nurnberg, who shared memories from his most recent visit with the author, whose first name was Nelle.

"Knowing Nelle these past few years has been not just an utter delight but an extraordinary privilege," Nurnberg said in a statement released by the publishing house.

"When I saw her just six weeks ago, she was full of life, her mind and mischievous wit as sharp as ever. She was quoting Thomas More and setting me straight on Tudor history. We have lost a great writer, a great friend and a beacon of integrity," Nurnberg said.

Michael Morrison, president and publisher of HarperCollins US General Books Group and Canada, said: “The world knows Harper Lee was a brilliant writer but what many don’t know is that she was an extraordinary woman of great joyfulness, humility and kindness.

She lived her life the way she wanted to -- in private -- surrounded by books and the people who loved her. I will always cherish the time I spent with her.”

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here.