A demonstrator dressed as a victim of a stoning execution joins Iranian exiles protesting against the possible stoning of Sakineh Mohammadi Ashtiani in Iran in front of the Brandenburg Gate on August 5, 2010 in Berlin, Germany.
A lawyer who defended a woman sentenced to be stoned to death in Iran is now in Turkey, according to the UN refugee agency.
Mohamed Mostafaei was detained in Turkey because of passport problems but has applied for asylum, the agency said.
He disappeared late last month after being summoned for questioning in Tehran.
Amnesty International accused the Iranian authorities of harassing him.
A well-known critic of the Iranian judicial system, Mr Mostafaei has been defending Sakineh Mohammadi Ashtiani, the mother-of-two facing execution for adultery.
Though the stoning penalty was lifted, she may still be executed by hanging.
Metin Corabatir, spokesman for the UN High Commissioner for Refugees (UNHCR) in Turkey, said Mr Mostafaei was in custody there and had applied for asylum in Turkey.
"The request will now be evaluated in co-operation with Turkish authorities," he said.
'Thorn in Iran's side'
I think stoning is such a barbaric death that I said that Brazil would receive this woman with open arms”
Luiz Inacio Lula da Silva
President of Brazil
Speaking to AFP news agency, Mr Corabatir said the UNHCR would look for third countries that would accept him.
"That is unfortunately a lengthy process but there are expedited tracks for vulnerable, high-risk people," he added.
In a statement after Mr Mostafaei was reported missing, Amnesty's Malcolm Smart described him as "a thorn in the side of the Iranian authorities".
Meanwhile, the Brazilian president, who has offered asylum to Ashtiani, has said that while it was important to "respect" other countries' customs, he could not condone capital punishment.
President Luiz Inacio Lula da Silva said that despite Brazil's "friendship" with Iran, he believed, as a Christian, that "only God can give life and only God can take it away".
"I think stoning is such a barbaric death that I said that Brazil would receive this woman with open arms, and could not kill her," he added.
Brazil told Iran that it was willing to provide refuge to Ashtiani after her case sparked widespread condemnation around the world.
Iran replied that President Lula was an "emotional" man who did not know the full details of the case.