Ganji held a press conference at his home shortly after his release on 29 May. He told journalists that his time in prison has made him even more determined to push for democratic changes in Iran. He said: "Even if I have to spend the rest of my life in prison, I will not change my views."
He was temporarily released after he threatened he would indefinitely continue his hunger strike to protest against his detention conditions.
In recent years, going on hunger strike has become a last resort for many Iranian political prisoners seeking to highlight their situations and to gain more rights.
Ganji said on 30 May that while he was not physically tortured in prison, he was placed under psychological pressure. He said he was denied rights granted to other prisoners. He called his imprisonment illegal and unfair and said that "all writers, journalists, and web-bloggers who are in jail" should be released. He said they have expressed their views without resorting to violence.
Several human rights groups, academics, and activists -- including Nobel Peace Prize laureate Shirin Ebadi -- had expressed concern over Ganji's deteriorating health and called for his release.
Ganji said he suffers from asthma and back pain.
French Media watchdog Reporters Without Borders (RSF) has called on EU foreign ministers and on Javier Solana, the EU's high representative for common foreign and security policy, to put pressure on Iran regarding Ganji's case. RSF is calling for an unconditional and definitive release of Ganji.
Reporters Without Borders spokesman Reza Moini says several factors contributed to Ganji's temporary release: "All observers should first consider Akbar Ganji's state and see what could have been the consequences of a person who goes on a hunger strike and is determined to continue [the strike] until [death]. I have no doubt that the Islamic Republic feels endangered in the current situation and I'm glad it takes some matters into consideration. In this case international pressures -- extensive activities by web-bloggers and journalists [also had an impact]. It was a big campaign for Akbar Ganji."
Other observers have suggested that Iranian leaders are showing leniency toward dissidents ahead of the country's presidential elections in order to encourage people to vote.
Ganji said on 30 May that the presidential elections could be one of the reasons for his release.
Ganji was jailed for 10 years in 2001 on charges ranging from harming Iran's national security to spreading lies against the Islamic Republic and its leaders.
His sentence was reduced to six years on appeal. His book: "The Dungeon of Ghosts" is a collection of his articles on the serial murders of dissidents and intellectuals in Iran.
In the bestseller he implicated Iran's former president and current presidential candidate Hashemi-Rafsanjani, former Intelligence Minister Ali Falahian, and several other conservative officials in the killings of four opposition leaders and writers in 1998.
Moini from Reporters Without Borders praises Ganji's courage and journalistic commitment in probing the sensitive issue of political murders.
"In his articles Ganji had written not only about the serial murders but he had also focused on the issue of political crimes. In relation to this he didn't just mention the four cases of murders that were recognized by the court -- but he mentioned more than 80 political murders inside and outside Iran. The issue of impunity form justice among leaders in Iran is important. It has always been, and Mr. Ganji -- and I also have to mention [prominent Iranian journalist] Emadeddin Baghi -- have made great efforts in this."
Mehrdad Mashayekhi, a professor of sociology at Georgetown University in Washington, is one of 60 professors who had called for Ganji's release in an open letter.
Mashayekhi said Ganji is a very influential figure in Iran's cultural and political scene. "He is one of the few people who started human rights activities in Iran," Mashayekhi said. "His disclosures about the serial murders [of intellectuals] and his courage are brilliant. He is also significant as a writer and also as someone who has bring many new terms in Iran's political literature."
It is not clear yet how long Akbar Ganji will be allowed to remain out of prison for medical treatment. Some Iranian papers have written that his leave will be extended indefinitely and that he will be freed.
Ganji said on 30 May that he has not accepted "any conditions" to being granted leave.
(Radio Farda correspondent Nazi Azima contributed to this report.)