Tehran (AFP) - Iran's award-winning human rights lawyer Nasrin Sotoudeh was arrested on Wednesday, her husband said in a Facebook post.
"A few hours ago Nasrin was arrested at home and transferred to Evin," Tehran's notorious prison where many political prisoners are held, her husband Reza Khandan wrote.
Sotoudeh, 55, one of the few outspoken advocates for human rights in Iran, recently represented several women arrested for protesting against the mandatory wearing of headscarves.
Tehran police said in February that 29 women had been detained for posing in public without their headscarves in the previous weeks.
Amnesty International called Sotoudeh's detention "an outrage".
The rights group said her husband had given an interview with Persian-language media outside the country, in which he said Sotoudeh was arrested to serve a five-year sentence of which they were completely unaware.
"Nasrin Sotoudeh has given her life to fighting for human rights in Iran. Her arrest today is the latest example of the Iranian authorities' vindictive attempts to stop her from carrying out her important work as a lawyer," Philip Luther, Amnesty's research director for the Middle East and North Africa, said in a statement.
Khandan's Facebook message was defiant, saying: "I once told interrogators in the interrogating room: 'Of all the things the authorities should do for their country, you only know one and that is arresting people.'"
Sotoudeh won the European Parliament's prestigious Sakharov rights award in 2012 for her work on high-profile rights and political cases, including juveniles facing the death penalty in the Islamic republic.
She spent three years in prison between 2010 and 2013 for "actions against national security" and spreading "propaganda against the regime" and remains banned from representing political cases or leaving Iran until 2022.
Sotoudeh has defended journalists and activists including Nobel Peace laureate Shirin Ebadi and several dissidents arrested during mass protests in 2009.
She had recently spoken out against a new criminal code that only allowed a small number of lawyers -- just 20 in Tehran -- to represent individuals charged with national security crimes.
"Permitting only lawyers who are pre-approved to defend individuals accused of 'security' offences -- who often include human rights defenders -- completely undermines the rights of detainees to a lawyer of their own choosing," said Amnesty's Luther.
During her time in jail, Sotoudeh staged two hunger strikes in protest at the conditions in Evin and over a ban on seeing her son and daughter.
She was released in September 2013 shortly before Iran's then newly-elected President Hassan Rouhani, who had campaigned on a pledge to improve civil rights, attended the UN General Assembly.