ISTANBUL (Reuters) - The lawyer who defended a woman sentenced to death by stoning in Iran is in Istanbul and has applied for asylum in a third country, a source at the United Nations’ refugee agency said Thursday.

Defense lawyer Mohammad Mostafaei disappeared from Tehran on July 24 after questioning by Iranian authorities, and his wife and brother-in-law were later arrested, according to an Amnesty International report.

“At the moment he is in Istanbul and he is in a facility where migrants are being held,” said the UNHCR source in Istanbul.

“He requested asylum and his claim has been registered,” said the UNHCR source, who added that his office was working with the Turkish government to find a third country that would take Mostafaei.

The source said the UNHCR and the government were in contact with several countries that might be willing to receive him.

Amnesty International called on Iran last month to end what it called the harassment of human rights lawyers.

Mostafaei is an outspoken critic of the Iranian judicial system, criticizing the execution of minors as well as the use of stoning in executions.

Most recently he defended Sakineh Mohammadi Ashtiani, whom Amnesty International said was convicted in 2006 of having an “illicit relationship” with two men.

She received 99 lashes as punishment, but was later convicted of “adultery while being married,” for which she was sentenced to death by stoning. She denied the charge.

Brazilian President Luiz Inacio Lula da Silva offered last week to give the woman asylum, but Iran rejected the offer on Tuesday.

The stoning sentence was suspended pending a review by Iran’s judiciary, but could still be carried out.

Turkey placed a geographical limit on the 1951 Geneva Convention on the Status of Refugees and takes only refugees from European countries.

Ankara works with non-governmental organizations and third countries to place non-European refugees, many of them from Iran, Afghanistan and Iraq.

Brazil and Turkey brokered a deal with Tehran earlier this year designed to help defuse tension between Iran and the West over the Islamic state’s nuclear program, but it was not enough to stop the United Nations, the European Union and Washington from imposing new sanctions on Iran.

Murder, adultery, rape, armed robbery, apostasy and drug trafficking are all punishable by death under Iran’s sharia or Islamic law, enforced since the 1979 Islamic revolution.