"Ms Sotoudeh is a strong voice for rule of law and justice in Iran. We are dismayed by her continued detention and loss of the right to practice law," US State Department spokesman P J Crowley said in a statement.

"Her conviction is part of a systematic attempt on the part of Iranian authorities to silence the defence of democracy and human rights in Iran," he said. Yesterday, Sotoudeh was sentenced for 11 years in prison.

Sotoudeh was reportedly convicted of acting against national security and failing to wear the Islamic head scarf. She was also banned from practicing law or travelling for 20 years.

"It is one in a series of harsh sentences targeting the lawyers of Iran's human rights community which perseveres despite threats, torture, and imprisonment," Crowley said.

"We call on the Iranian government to address the international community's 'deep concern at serious human rights violations in Iran' as expressed in the December UN General Assembly resolution and to respect its human rights obligations, including its obligations under the International Covenant on Civil and Political Rights," he added.