CAIRO -- An international rights group is urging Iran to release the son and the lawyer of an Iranian woman who has been sentenced to death by stoning for adultery.

The call by Amnesty International comes as fears grow that 43-year-old Sakineh Mohammadi Ashtiani could also be soon executed for murder.

The London-based group says Ashtiani's son, Sajjad Qaderzadeh, and lawyer Houtan Kian were arrested Oct. 10, along with two Germans seeking to interview the son.

Amnesty's Iran expert Ann Harrison says the detentions are "very worrying" and that with both her son and lawyer arrested, Ashtiani has no one left to defend her.

The case triggered an international outcry and elevated tensions between Iran and the West.

Tehran temporarily suspended the stoning verdict, suggesting Ashtiani might be hanged instead.