A Canadian-Iranian photojournalist arrested in Iran died of a brain haemorrhage resulting from a blow to the head that caused a skull fracture, an official inquiry has concluded.
Zahra Kazemi was arrested while taking photos of Evin prison
The report said that Zahra Kazemi died after "either a hard object struck her head, or her head struck a hard object", without specifying how the blow was sustained.
Earlier, Iran acknowledged that Ms Kazemi, 54, had been beaten to death after her arrest on 23 June for taking pictures of Tehran's Evin prison. She was later pronounced dead after falling into a coma.
The new report - providing an hour-by-hour development of the incident - said that a medical committee had found "no traces of blows or injuries" to the head other than the fatal fracture.
It said the blow occurred up to 36 hours before Ms Kazemi was admitted to hospital on 26 June and called for a further inquiry to question all those in contact with her during that time.
On Sunday, Iranian reformist lawmakers demanding the resignation of Tehran's hardline Prosecutor General Saeed Mortazavi, after accusing him of failing to prevent Ms Kazemi's death.
"Instead of respecting the dignity of journalists and the reputation of the Islamic republic by punishing those who beat her, Mortazavi ordered her to stay in detention," MP Mohsen Armin was quoted as saying by AFP news agency.
Earlier, officials in Tehran refused to allow Canada to conduct its own investigation into the photographer's death.
The Iranian authorities initially said Ms Kazemi had died of a stroke after falling ill during her first police interview.
Stephan Hachemi wants an independent autopsy in Canada
Her relatives insisted she had been tortured and beaten into a coma by her interrogators.
Iran's President Mohammad Khatami ordered four ministers to investigate the death of the freelance photographer.
Relations between Tehran and Ottawa have become strained over the case.
Canadian Deputy Prime Minister John Manley had said that bilateral relations would be damaged if Ms Kazemi's body was not returned.
But Iran's Interior Minister Abdolvahed
Moussavi-Lari said Ms Kazemi's death had nothing to do with Canada "since she is an Iranian citizen".
Ms Kazemi, who held an Iranian passport, was in Tehran to take pictures of the recent student protests for the British agency Camera Press.
Her son, Stephan Hachemi, 26, has demanded that her body be returned to Canada for an independent autopsy.
Mr Manley said Ms Kazemi's death had become "a very serious issue".
"We believe the family, of course, deserves a full explanation for what happened," he said.
"The body should be returned."