The official news service Agencia Brasil reports that Brazilian ambassador to Iran Antonio Luis Espinola Salgado made the offer Monday.
The case created an international outcry when Sakineh Mohammadi Ashtiani was sentenced to death by stoning. Iran has withdrawn that punishment, but the mother of two could still face execution by hanging.
On July 31, Brazilian President Luiz Inacio Lula da Silva suggested he would be willing to provide the woman refuge.
Silva said that if the woman "is causing problems there, we will welcome her here."