An Iranian teenager was sexually assaulted and killed by three men working for Iran's security forces, a leaked document seen by BBC Eye Investigations says.

16-year-old Nika Shakarami disappeared during an anti-regime protest in 2022.

The Woman, Life, Freedom movement had been sparked just days earlier by the death of a 22-year-old woman, Mahsa Amini.

Nika's body was found nine days after she disappeared. The government claimed she killed herself.

The BBC put the report's allegations to Iran's government and its Revolutionary Guards. They did not respond.