Iranian media reports say three senior judicial officials have been suspended over the killings of three anti-government protesters in prison last year.
The move clears the way for the trio, who were not named, to face trial.
One of the slain prisoners was 24-year-old Mohsen Rouhalamini, the son of a prominent conservative politician. His death sparked an outcry even among government supporters.
More than 150 demonstrators were arrested and taken to Kahrizak detention center south of Tehran in the aftermath of street protests against President Mahmoud Ahmadinejad's disputed re-election in June 2009. Political opposition groups say the prisoners were abused, tortured and killed in the Kahrizak prison during the post-election unrest.
The opposition says more than 80 protesters were killed in the crackdown. The government has confirmed about 30 deaths.
Iran's Supreme Leader Ayatollah Ali Khamenei ordered the closure of Kahrizak jail in July, following widespread outrage in Iran over the reports of abuse.
In June, two prison officials were sentenced to death on charges of torturing and killing the three opposition protesters. Nine others were sentenced to prison terms and flogging as a result of the case.
Some information for this report was provided by AFP and AP.