Karoubi’s family said emergency medical services and ministry of intelligence doctors gave permission for him to be rushed to hospital on 24 July after examining him at his home.

During his six years under house arrest, Karoubi, 79, has been hospitalized six times because of heart problems and other ailments linked to the conditions in which he is being held and his inability to leave his home.

The ministry of intelligence has turned part of his house into a prison with 12 guards, who prevent family members from visiting him.

Karoubi’s son, Taghi Karoubi, told RSF: “President Hassan Rouhani took advantage of his credibility and popularity with the Green Movement’s supporters during his two elections but has done nothing to get him released. Rouhani could at least ‘legalize’ the conditions of his house arrest and remove the intelligence ministry officers from his home. But he has done nothing.”

Reza Moini, the head of RSF’s Iran/Afghanistan desk, said: “The Rouhani government must terminate this situation and keep its promise to the millions of Iranians who have been calling for an end to the house arrest of Mehdi Karoubi, Mir Hossein Mousavi and Mousavi’s wife.

“Rouhani should not forget that it was his undertakings to defend free speech and media freedom and to release political prisoners that persuaded Iranian progressives, especially young people and women, to vote massively for him.”

Karoubi, the owner of the now closed newspaper Etemad Melli, Mir Hossien Mousavi, the owner of the now closed newspaper Kalameh Sabaz, and Mousavi’s wife, the writer Zahra Rahnavard, have been illegally subjected to house arrests and deprived of all their rights since February 2011.

These leaders of the protests against President Mahmoud Ahmadinejad’s disputed reelection in June 2009 are regarded by the regime as “leaders of sedition.”

RSF points out that the arbitrary detention of Karoubi, Mousavi and Rahnavard has no legal basis under either Iranian law or international standards. As they are denied the right to a fair trial, their detention is a flagrant violation of the Universal Declaration of Human Rights.

Iran is ranked 165th out of 180 countries in RSF’s 2017 World Press Freedom Index.