Opposition groups in Iran say police have been trying to execute an arrest warrant on the lawyer of a woman sentenced to be stoned to death for adultery.

The case has caused an international outcry against Iran, which ordered a temporary reprieve for the woman.

A leading opposition website reported that security police went to the offices of lawyer Mohammed Mostafaie armed with an arrest warrant.

His wife and her brother were taken into custody but there was no word on the whereabouts of the lawyer, who is a well-known human rights activist.

Supporters said he invited arrest by speaking to foreign media outlets about the case of his client, 43-year old mother-of-two Sakineh Mohammadi Ashtiani, who was sentenced to death by stoning after being found guilty of adultery.

In a separate case, award winning Iranian journalist and anti-death penalty campaigner, Emadeddin Baghi, has been sentenced to a year in prison and a five-year ban from political activity for forming a group for the rights of prisoners.