A committee of the Iranian parliament has made a rare official criticism of treatment of opposition detainees held in the wake of the disputed election, BBC reported.
The report said three detainees died at the notorious Kahrizak detention, and it blamed the former Tehran prosecutor.
The report is heavily critical of the way detainees were sent to the centre, despite a lack of space and facilities.
The report says that 147 of them were kept in one room, with poor food, excessive heat, and poor ventilation.
It says that three of them died because of the bad conditions, and as a result of physical attacks.
The parliamentary committee blames a former Tehran prosecutor, who had a reputation as a hardliner, for insisting the detainees be sent there despite being warned about the conditions.
The prosecutor, Saeed Mortazavi, has since been moved to another job, though there is no word if any other action is being taken against him.
The detention centre itself was closed in July by order of Supreme Leader Ayatollah Khamenei.
The report strongly denies a number of other allegations that opposition detainees have been raped, and otherwise mistreated in custody.
Nevertheless, it is a rare example in which the government has accepted allegations of brutal treatment of opposition supporters in the wake of the disputed presidential election.