Kazemi died after being arrested in Tehran

Shirin Ebadi, a human rights lawyer, will act for Zahra Kazemi's family in the trial of an intelligence agent charged with beating her to death.

Ms Kazemi died in July, three weeks after she was detained while taking pictures outside a Tehran prison.

Ms Ebadi won the Nobel prize this year for her human rights campaigning.

Intelligence agent Mohammad Reza Aghdam Ahmadi went on trial for Kazemi's murder last month.

The next hearing has been delayed to allow the family's lawyers to research the case.

"Shirin Ebadi has accepted a request from the mother of Zahra Kazemi to represent the family," a spokesman for the Human Rights Defence Circle said.

"She has delegated part of her powers to three members of the circle who will represent the family in the trial but Shirin Ebadi will supervise the work and intervene when the need arises," he said.

The case has sparked a fierce debate between the hardline judiciary and the reformist intelligence ministry.