Iran's Supreme Leader Ayatollah Ali Khamenei will pardon 10,000 prisoners including political ones in honor of the Iranian new year on Friday, state TV reported.

An Iranian medic treats a patient infected with COVID-19 at a hospital in Tehran on Sunday. Photo: AFP

"Those who will be pardoned will not return to jail ... almost half of those security-related prisoners will be pardoned as well," judiciary spokesman Gholamhossein Esmaili told state TV on Wednesday.

On Tuesday, Esmaili said Iran had temporarily freed about 85,000 people from jail, including political prisoners, in response to the coronavirus epidemic.

"A large number of prisoners who have been temporarily freed do not need to return to jail after the leader's pardon," Esmaili said.

"The unprecedented point is that the pardon also includes the security-related prisoners with less than five-year jail sentences," Esmaili said.

Esmaili did not say whether it would include British-Iranian aid worker Nazanin Zaghari-Ratcliffe, who was released on Tuesday for two weeks.

Iran said it had 189,500 people in prison, according to a report that the UN Special Rapporteur on human rights in Iran, Javaid Rehman, submitted to the Human Rights Council in January. They are believed to include hundreds arrested during or after anti-government protests in November 2019.

The coronavirus outbreak has prompted calls from the UN and the US for political prisoners, including dozens of dual nationals and foreigners, to be released from Iran's overcrowded and disease-ridden jails.

Washington has warned Iran that it would hold the Tehran government directly responsible for any American deaths in jail.

Iran's elite Revolutionary Guards have arrested dozens of dual nationals and foreigners over recent years, including citizens of the US, Britain, Canada, Australia, Austria, France, Sweden, the Netherlands and Lebanon.