Iran's Atomic Energy Organisation claimed on Sunday that one of its subsidiary's email servers had been compromised in a "foreign" attack meant to attract "notice" amid demonstrations against Mahsa Amini's passing.
Demonstrations that have lasted for weeks have been spurred by the death of 22-year-old Amini on September 16 after she was arrested for allegedly breaking the tight dress code for women in the Islamic republic.
Numerous people have died as a result of the street violence, predominantly protestors but also security personnel, and hundreds more protesters have been detained.
Black Reward, an organisation, gave Tehran a 24-hour deadline to release all "political prisoners, prisoners of conscience, and anyone captured in the recent rallies" or it will release papers on Tehran's nuclear programme.
Material on social media said to be released by the group on Saturday included a short clip from a purported nuclear site in Iran, as well as documents containing agreements, maps and payslips.
The nuclear agency acknowledged in a statement that a hack had targeted its subsidiary, the Atomic Energy Production and Development Company, but downplayed the importance of the documents.
“Unauthorised access by a source originating from a specific foreign country to the email system of this company led to the publication of the content of some emails on social media,” it said in a statement.
These emails contain “technical messages and normal and daily exchanges”, it added.
“The purpose of such illegal efforts, which are made out of desperation, is to attract public attention, creating media atmospheres and psychological operations,” the statement continued.
Iran in 2015 reached a landmark deal with world powers, after years of negotiations over its nuclear programme.
The agreement, known formally as the Joint Comprehensive Plan of Action (JCPOA), gave Iran sanctions relief in return for restricting its nuclear programme.
It was derailed in 2018 when then-president Donald Trump unilaterally withdrew the United States from it, but on-off talks have taken place since April 2021 in an effort to revive it.