Tehran, Iran (CNN) -- An attorney representing an imprisoned Iranian woman facing possible execution by stoning remained missing Tuesday, although his wife and brother-in-law were in custody, a human rights activist said.
Mohammad Mostafaei's wife and brother-in-law were being held at Tehran's Evin prison, said Mina Ahadi, chairwoman of the International Committee against Execution and Stoning. Neither has had access to a lawyer, she said.
Mostafaei's father-in-law was contacted by officials Monday, who told him that both his children would be freed in exchange for Mostafaei himself, Ahadi said. She said Monday that Mostafaei's office has been closed.
Mostafaei represents Sakineh Mohammadie Ashtiani, who was convicted of adultery in 2006 and was originally sentenced to death by stoning. The sentence was put on hold earlier this month after an international outcry.
Protesters rallied worldwide Saturday in support of Ashtiani, pushing for her release.
Earlier this month, Mostafaei told CNN that his client confessed to the crime after being subjected to 99 lashes with a whip. She later recanted the confession and has denied wrongdoing, he said.
Iranian state media reported this month that the nation's judiciary chief halted the execution of Ashtiani.
"Although the verdict still stands and is definite, the execution has been halted on humanitarian grounds from the order of the honorable judiciary chief, and will not be implemented at this time," Malek Ajdar Sharifi, a judiciary official in East Azerbaijan province, told Iran's Islamic Republic News Agency.
There is no clear timeline for Ashtiani's case, Ahadi said Tuesday. The imprisoned woman has two attorneys, and Ahadi was expecting an update from the second. He must get an appointment with authorities in order to move forward on the case, she said.
CNN's Mila Sanina contributed to this report.