Aghajari said Muslims should not follow clerics "like monkeys"
Hashem Aghajari is a history professor at one of Tehran's universities and a disabled veteran of the 1980-88 war with Iraq.
He is an active member of the reformist Organisation of the Mujahideen of the Islamic Revolution (Mujahideen-e Enqelab-e Eslami).
He was sentenced to death for apostasy in November 2002.
He had enraged conservatives in June that year, when he questioned the rule of clerics and the principle of emulating religious leaders.
He said Muslims should not follow Islamic clerics "like monkeys". Many accused him of being Iran's Salman Rushdie.
The sentence sparked off a month of student protests.
Supreme Leader Ayatollah Khamenei then ordered a judicial review of the case.
Though Iran's Supreme Court quashed the death sentence in February 2003, the case was promptly sent back for retrial by the very court that ordered the execution.
Judiciary spokesman Gholamhussein Elham said the court of the first instance must "correct procedural failings and issue a new judgement" - which, he said, "could be the same as the first".
In May 2003 Mr Aghajari refused to attend the first day of his retrial, in the north-western city of Hamedan.
His lawyer told the BBC that, in view of strong local feeling against his client, he had asked for the case to be transferred to Tehran.
In June 2003, against a backcloth of pro-reform demonstrations in Tehran, Mr Aghajari was reported to be among 250 intellectuals who issued a strongly-worded declaration accusing the ruling clerics of setting themselves in the place of God.
BBC Monitoring, based in Caversham in southern England, selects and translates information from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages.