According to a statement on the International Committee Against Stoning (ICAS) website, Sakineh Mohammadi Ashtiani's son Sajjad Ghaderzade and lawyer Javid Hutan Kian have been tortured since being arrested earlier this month.
"According to information obtained (on) stoning and executions, Sajjad, the son of Sakineh and Houtan Kian, her lawyer, are subjected to pressure and severe torture in a prison of Tabriz," the statement said.
Ghaderzade and Kian were arrested earlier this month. The two German journalists conducting their interview were also detained.
Following international pressure, Iranian authorities suspended the stoning sentence against Ashtiani. But there are fears she could be executed by hanging.