Arrested in September 2010, Sotoudeh was serving a six-year term for spreading propaganda and conspiring to harm state security. Sotoudeh, 50, who defended journalists and rights activists including Nobel Peace laureate Shirin Ebadi, went on hunger strike for nearly 50 days last year to force authorities to repeal a travel ban on her young daughter.
The prison releases come less than a week before President Hassan Rouhani addresses the U.N. General Assembly for the first time and is expected to present a less confrontational image than Ahmadinejad, under whose eight years in power Iran came under ever-tougher Western trade sanctions.
One of the other prisoners released on Wednesday was Mohsen Aminzadeh, a former deputy foreign minister under reformist former President Mohammad Khatami, who supported reformist presidential candidate Mirhossein Mousavi in 2009. Feizollah Arabsorkhi, a former deputy minister of commerce under Khatami, was also released. The total number of prison releases was not immediately clear, but various news reports mentioned seven other women and three men in total.