Nasreen Shakarami has said authorities kept her daughter's death a secret for nine days and then snatched the body from a morgue to bury her in a remote area against the family's wishes.
The mother of a 16-year-old Iranian girl has said she was killed by blows to her head as part of the crackdown on anti-hijab protests across the country.
Nasreen Shakarami disputed official claims her daughter Nika fell to her death from a high building.
She also said authorities kept the teenager's death a secret for nine days and then snatched the body from a morgue to bury her in a remote area against the family's wishes.
Nika Shakarami has become the latest icon of the protests, which were sparked by the death of 22-year-old Mahsa Amini in the custody of Iran's morality police.
They had detained her for allegedly violating the country's strict Islamic dress code.
Young women have defiantly torn off and waved their headscarves as they led the protests, which have called for the overthrow of the Iranian regime.The protests quickly spread across Iran and have been met by a harsh government crackdown, including beatings, arrests and the killing of demonstrators
At least four public fountains in the capital Tehran have been dyed red, according to social media posts, by an artist for a work entitled Tehran Drowned in Blood.
Human rights groups estimate dozens of protesters have been killed over the past three weeks.
On Thursday Amnesty International accused the Iranian security forces of killing at least 66 people, including children, and wounding hundreds after firing live rounds at protesters, bystanders and worshippers in the city of Zahedan on 30 September.
Iran has claimed the violence involved unnamed separatists. More than a dozen people have been killed in the area since then, the report said.
In a video message to Radio Farda, the Persian-language arm of the US-funded Radio Free Europe/Radio Liberty, Ms Shakarami disputed attempts by officials to frame her daughter's death as an accident.
She said forensics reports showed Nika had died from repeated blows to the head.
Her body was intact, but some of her teeth, bones in her face and part of the back of her skull were broken, she said.
"The damage was to her head," she said. "Her body was intact, arms and legs."
Earlier this week Iran's police chief, General Hossein Ashtari, claimed the teen had gone to a building "and fell from the upper floor at a time of gatherings". He said "the fall from that height led to her death".
Ms Shakarami said her daughter left her home in Tehran on the afternoon of 19 September to join the anti-hijab protests.
She said she was in touch with Nika by phone several times over the next few hours and pleaded with her to come home. They last spoke before midnight.
"Then Nika's mobile was off, after she and her friends were shouting names of forces while they were fleeing," sh