Allegations that election protesters were tortured and raped in detention must be urgently investigated by the Iranian authorities, Amnesty International's Secretary General said on Saturday.
Irene Khan called on Iran's Supreme Leader Ali Khamenei to institute an immediate, independent inquiry into the allegations, and to invite international experts – including the UN's experts on torture and extrajudicial killings - to help carry it out.
"Reports emerging from Iran allege that both men and women detainees have been tortured, including by rape … in some cases causing their deaths," said Irene Khan.
"The forms of abuse described appear to have been intended to degrade and humiliate the victims in the most extreme way. If the allegations are well-founded those responsible must be brought to justice without delay."
A recent investigation reported to have been conducted by the Iranian parliament found no evidence of rape or other torture of detainees, according to parliament speaker Ali Larijani.
However, Ayatollah Khamenei had earlier ordered the closure of Kahrizak detention centre and announced that the prison's chief and several guards had been dismissed for abuse of prisoners.
"If Speaker Larijani's denial is to have credibility, we need to know the details of the parliamentary investigation to which he refers, including who carried it out and whether it could be considered independent," said Irene Khan.
"We are urging the Speaker to make the details known and to publish the full findings of the investigation so that the world can assess whether it can be considered credible, or was merely an attempt to deflect criticism and cover up the truth."
On Friday, Mehdi Karroubi, one of the four candidates permitted to stand in the 12 June presidential election, alleged that a number of detainees held for protesting against the disputed official result of the election had been beaten to death in detention.
Previously, on 9 August, he alleged that detainees had been tortured, including by rape, and called for an urgent inquiry. It was shortly after this, in the face of mounting international concern, that the Speaker said the allegations had been dismissed by a parliamentary inquiry.
Mohsen Rouhalamini, son of a top aide to presidential candidate Mohsen Rezaei, is reported to have died of cardiac arrest and bleeding in his lungs two weeks after he was detained on 9 July. He is believed to have been held at Kahrizak and was alleged to have had serious facial injuries.
Ayatollah Khamenei is reported to have ordered an investigation into his death. Soon afterwards, he ordered the closure of Kahrizak detention centre.
"The Supreme Leader must act, and act now, to address the spiral of abuse," said Irene Khan.
"Official denials are not enough. What is needed is a root and branch investigation into the allegations of torture, including rape, and other abuses, and the Supreme Leader should invite international experts – such as the UN special rapporteurs on torture and on extrajudicial, summary or arbitrary executions – to visit Iran and participate in the investigation, if it is to have credibility at home and abroad."