An Iranian official on Thursday ordered an inquiry into allegations of rape and sexual assault of inmates in jails, the judiciary said.
Reports — denied by the authorities — of prisoners being sexually assaulted appeared last month in international media.
The assaults allegedly took place during the anti-government protests that rocked the country following the death of Mahsa Amini.
The Iranian-Kurd, 22, was detained by for wearing her hijab “inappropriately”.
“Vice president of the judicial authority for international affairs and secretary of the High Council for Human Rights Kazem Gharibabdi has asked the country's prosecutor general to carry out a thorough investigation into the allegations of sexual assault and rape of some inmates”, the judiciary's Mizan Online news website said.
On Wednesday, judiciary spokesman Massoud Setayeshi denounced the “false libellous assertion” of “sexual harassment against female detainees”. He said it had been amplified by “some media outlets hostile” to the country.
On December 8, Iran's prison service denied women were sexually assaulted inside its jails and threatened to file charges against those making such allegations.
“Given the very negative effect of these claims, please carefully study and address these accusations, whether raised inside the country or outside of it,” Mr Gharibabdi wrote in a letter to prosecutor general Mohammad Jafar Montazeri quoted by Mizan.
“Before anything else, proof must be sought from the people expressing these claims,” he said.
Mr Gharibabdi called on the prosecutor general to bring to justice “the perpetrators or those making such allegations, depending on the result of the investigation”.
Iran has been gripped by unrest since Ms Amini's death on September 16 following her arrest.
Iranian officials generally describe the protests as “riots”. They say hundreds have been killed, including members of the security forces, and thousands arrested.