The Iranian authorities have admitted that three of the opposition protesters jailed after the country's disputed presidential election in June were beaten to death.
A statement by the Iranian judiciary says that a medical examination of the three bodies has shown the cause of death was not meningitis, as previously claimed.
The Isna news agency, quoting a prosecution office statement, has named the three killed as Mohsen Ruholamini, Amir Javadi and Mohammad Kamrani.
They were among more than 150 demonstrators taken to the Kahrizak detention centre south of Tehran after street protests, the BBC reports.
Officials had earlier said that Mr Ruholamini and Mr Kamrani had died of meningitis but the prosecution office said: "The coroner rejected that these people died of meningitis and confirmed there were bruises on their bodies from beatings and that the cause of death was a series of beatings."
Three charged with murder; centre already closed
Three people working at the detention centre have been charged with murder and nine others charged in relation to the deaths.
The centre was shut in July, after Iran's supreme leader, Ayatollah Ali Khamenei, said it had failed to "preserve the rights of detainees".
Iran's opposition leaders have long claimed that some protesters - about 200 of whom remain behind bars - have been abused in prisons and other places of detention. At least five have been sentenced to death.
President Mahmoud Ahmadinejad's re-election triggered mass protests by Iranians who believed the voting had been rigged.