An Iranian coroner's report into said she did not die due to blows to the head and limbs but from multiple organ failure caused by cerebral hypoxia, the official news agency IRNA reported on Friday.
The death of 22-year-old Amini while in the custody of has ignited Her father has said she suffered bruises to her legs, and has held the police responsible for her death. Witnesses and other family members also said she was beaten during his arrest.
The coroner's report claimed her death was "not caused by blow to the head and limbs". It did not say whether she had suffered any injuries.
The report did say she fell while in custody due to "underlying diseases".
The Iran Forensic organisation added that her death was related to "surgery for a brain tumour at the age of eight", also saying that the report included CT scans of the brain and lungs, an autopsy and pathological tests.
"Due to the ineffective cardio-respiratory resuscitation in the first critical minutes, she suffered severe hypoxia and as a result brain damage," the report continued.
Dozens of people have been killed as Iranian security forces cracked down on protests which followed Amini's death.
Iran has frequently covered up the death of protesters, saying young people killed at protests died of natural causes or suicide, activists say.
(Reuters and °®Âþµº Staff)