TEHERAN - The death of Iranian Kurdish woman Mahsa Amini was caused by illness rather than blows or beatings, said an official medical report published on Friday, three weeks after she died in custody.

Iran's Forensic Organisation said "Mahsa Amini's death was not caused by blows to the head and vital organs and limbs of the body", in its report published on state television.

Her death was related to "surgery for a brain tumour at the age of eight", the same source added.

Amini, 22, was arrested on Sept 13 in Teheran for "inappropriate attire", and died three days later while in custody.

The authorities have previously said she suffered a heart attack after being taken to a station to be "educated".

Her family have denied she had any heart problems. Her father has said she had bruises on her legs, and holds police responsible for her death. One of her cousins living in Iraq has told AFP she died of “a violent blow to the head”.

Amini's death ignited protests across Iran.

Rights groups say more than 150 people have been killed, hundreds have been injured and thousands arrested in a crackdown on the protests, which also mark the biggest challenge to Iran's clerical leadership in years.

Women have played a prominent role, waving and burning headscarves. High school girls have also taken part. 

Referring to the day she collapsed in custody, the coroner’s report said Amini had regained consciousness before falling again due to what it described as underlying diseases.

“Due to the ineffective cardio-respiratory resuscitation in the first critical minutes, she suffered severe hypoxia and as a result brain damage despite recovery from cardiac functioning,”it said.

“She died due to multiple organ failure caused by cerebral hypoxia.”

The lawyer for Amini’s family, Saleh Nikbakht, previously told the semi-official Etemadonline news website that “respectable doctors” believe she was hit in custody.

The police have denied she suffered any harm.

Other young girls have lost their lives at the protests, but Amnesty International says Iran has been forcing televised confessions out of their families to “absolve themselves of responsibility for their deaths”.

The mother of 16-year-old Nika Shahkarami, who died after going missing on Sept 20, insisted on Thursday she was killed by the state after joining an anti-hijab protest in Teheran.

Nasrin Shahkarami also accused the authorities of threatening her to make a forced confession over the death of her daughter Nika.

“I saw my daughter’s body myself... The back of her head showed she had suffered a very severe blow as her skull had caved in. That’s how she was killed,” she said in a video posted online by Radio Farda, a US-funded Persian station based in Prague.

Iran has since denied reports its security forces killed another teenage girl, Sarina Esmailzadeh, at a rally in Karaj, west of Teheran. Its website quoted a prosecutor as saying an investigation showed Esmailzadeh, 16, had “committed suicide” by jumping from a building. AFP, REUTERS