She has not been informed of any charge against her.
Any action against Ms Ebadi would damage Iran’s image in the international community at a time when Tehran is already under pressure over allegations from the United States that it is pursuing a nuclear weapons programme.
Ms Ebadi’s unexpected Nobel victory in 2003 was a huge source of pride to most Iranians. But her sudden global recognition was deeply embarrassing to religious hardliners whom she had infuriated by defending many high-profile political dissidents.
Yesterday, Ms Ebadi said she had "no idea" why she had been summoned to appear before the Revolutionary Court, which deals with national security offences and has jailed many outspoken dissidents in the past. "I am a lawyer and I know the limitations of my activities," she said. "Therefore I have done nothing illegal and I don’t know why I have been summoned."
The summons puzzled most analysts, who suspected it was an attempt by Iran’s unpopular old guard to flex its muscles. If so, it is likely to backfire.
Ms Ebadi’s profile has not been particularly high recently, and some observers have argued she has not been as vocal as they had hoped she would be when she became a Nobel laureate.
Expectations that the prize would boost the country’s embattled reformist camp, led by the president, Mohammad Khatami, have been disappointed. Reformists were decisively beaten in parliamentary elections last year after most of their candidates were disqualified by the conservative Guardian Council.
There was speculation the old guard was reacting to a recent Iranian press report which said Ms Ebadi could run for president in June’s elections, although she is said to have denied any such intention. She has insisted consistently that she will keep out of politics, confining her work to the legal field.
Yet hardliners have no shortage of grievances against Ms Ebadi, 57, whom they view as an agent of the West bent on undermining Iran’s Islamic values. She has called for the freeing of all political prisoners, a category the hardline judiciary insists does not even exist.
Ms Ebadi has also taken on several high profile cases, including one involving Zahra Kazemi, a Canadian journalist who died in custody in 2003 after receiving a blow to the head in a Tehran prison that split her skull.
Ms Ebadi was also recently refused permission to stage a peaceful rally to protest the executions of under-18-year-olds in the Islamic Republic.
Officials explained there was no need for such an event because the judiciary was drafting a bill to limit death verdicts against under-18s.
In 2000 Ms Ebadi was accused of distributing a video-taped confession of a hardliner who claimed that prominent conservative leaders were instigating physical attacks on pro-reform figures. She spent three weeks in jail after a closed trial, was given a suspended 18-month sentence and banned from working for a lawyer for five years.
She had been her country’s first female judge but lost the job after the 1979 Islamic Revolution, when ruling clerics decided that women were by nature unsuitable for such posts. She then worked relentlessly to defend human rights, particularly those of women and children.
She has complained of increased threats since winning the Nobel Prize.