Mohammadi, who won the peace prize in 2023 in recognition of more than two decades of campaigning, was arrested on December 12 in the eastern city of Mashhad after speaking out against Iran's clerical authorities at a funeral ceremony.

In February, without prior warning, she was moved to a prison in the northern city of Zanjan and has only been allowed the most limited communication with her family, with concerns amplified by the US-Israel war against Iran during which the city has been attacked.

However her legal team, accompanied by one family member, were finally allowed to visit her in prison in Zanjan on Sunday "under heightened security surveillance", her supporters said in a statement.

"Her general health was extremely poor, and she appeared pale and weak with significant weight loss when brought to the visitation room by a prison nurse," the statement said, adding: "Her life is in imminent danger."

It said that on March 24 Mohammadi was found "unconscious in her bed, with her eyes rolled back" in a state that lasted over an hour.

But she was treated only in the prison infirmary and not taken to hospital "despite this medical emergency and evident indications of a heart attack", it said.

Nearby US-Israeli strikes and massive explosions can be heard from within the prison, adding to her "severe stress", the statement said.

Mohammadi was arrested before protests erupted nationwide later in December 2025. The movement peaked in January, with authorities launching a crackdown that activists say killed thousands of people.

In February, she was handed a further six years in prison on charges of harming national security and a one-and-a-half-year prison sentence for propaganda against Iran's Islamic system. She also went on hunger strike for almost a week to protest her conditions of detention.

Over the past quarter of a century, Mohammadi, 53, has been repeatedly tried and jailed for her campaigning against Iran's use of capital punishment and the mandatory dress code for women.