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.

Soutoudeh and husband Reza Khandan at the place where one of the most famous protests against the mandatory wearing of the hijab happened

The 'girl with the white flag' became a pin-up of the movement when she took off her headscarf in public in the capital of Tehran in December

Nasrin Sotoudeh in conversation outside the walls of the notorious Evin prison near Tehran

Tehran police said in February that 29 women had been detained for posing in public without their headscarves in the previous weeks.

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.

The Evin prison in Tehran set against the dramatic backdrop of the snow-capped Alborz mountain range to the north of the capital

A group of women wearing headscarves in their cell in Evin prison with several bunk beds crammed into a single room

Ms Sotoudeh has already spent three years in prison between 2010 and 2013 for 'actions against national security'

Sotoudeh has defended journalists and activists including Nobel Peace laureate Shirin Ebadi and several dissidents arrested during mass protests in 2009.

During her time in jail, she staged two hunger strikes in protest at the conditions in Evin and over a ban on seeing her son and daughter.

Sotoudeh revealed that beatings, torture, mock executions and brutal interrogations are all regular occurrences at the prison - which is home to over 15,000 inmates.

Those bound to life inside the jail include killers, thieves and rapists but also journalists, intellectuals and dissidents.

Sotoudeh 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.

Iranian lawyer Nasrin Sotoudeh (left) speaks on the phone next to her husband Reza Khandan (right) as they pose for a photo in their Tehran home in September 2013