Atefeh Rangriz, a well-known writer and women's rights activist in Iran, has been arrested amid an intensifying clampdown on civil society.
Rangriz conveyed the news to her family on September 10 during a brief phone call from Semnan prison, some 200 kilometers from Tehran.
She did not provide any information about the charges against her or the circumstances of her arrest.
She had been detained several times in the past for her activism, most recently in May 2019. Rangriz was sentenced to 11 years and six months in prison but was later released under an "amnesty."
The Iranian authorities, fearing a flare up in protests ahead of the September 16 anniversary of Mahsa Amini's death in police custody, have ramped up their crackdown on activists in recent months.
Last month, security forces arrested 12 women's rights activists in the northern province of Gilan.
The detainees were reportedly subjected to physical abuse and denied basic rights while in detention.