Lubna Hussein was convicted on indecency charges on Monday in a case that has attracted a worldwide outcry, and was ordered to pay a fine or face a month in jail, but was spared a penalty of 40 lashes.
Hussein, arrested at a Khartoum party in July along with 12 other women, had told Reuters after the verdict that she would refuse to pay the fine, preferring to go to jail instead as a means of challenging the law's legitimacy.
"They just came to me in the prison minutes ago and told me I have to go. I have no idea why. I am not happy. I told all my friends and family not to pay the fine," she told Reuters. "But I have been freed."
"I am also not happy because there are more than 700 women still in the prison who have got no one to pay for them."
Hussein, a former reporter working for the United Nations at the time of her arrest, said she believed there had been political pressure to free her and bring an end to a high profile case seen as a test of Sudan's decency regulations.
Mohieddin Titawi, chairman of the journalists' union, said his group had paid the fine because it had a responsibility to "protect journalists when they are in prison". His organisation is seen by many journalists as having links to the government.
Decency Regulations Vague
The United Nations human rights office said Hussein's conviction violated international law and was emblematic of wider gender discrimination in the Islamic country.
"Lubna Hussein's case is in our view emblematic of a wider pattern of discrimination and application of discriminatory laws against women in Sudan," U.N. human rights spokesman Rupert Colville told a news briefing in Geneva.
"No defence witnesses were heard. It is not clear there is a chance to appeal," he told Reuters.
Many women activists say Sudan's decency regulations are vague and give individual police officers undue latitude to determine what is acceptable clothing for women. Hussein's lawyer has said he planned to appeal against her sentence.
Hussein had faced the possibility of 40 lashes for wearing trousers deemed indecent. Ten of the women arrested with her were flogged in July, she has said.
Hussein has publicised her case, posing in loose trousers for photos and calling for media support.
Women have often been convicted of similar offences under Sudan's Islamic decency regulations in recent years and sentenced to beatings, Hussein's supporters say. They say she is the first to challenge such treatment.
Hussein has said she resigned from her U.N. job to give up any legal immunity so she could continue with the case, prove her innocence and challenge the decency law.
U.N. officials have said the United Nations told Sudan that Hussein was immune from legal proceedings as she was a U.N. employee at the time of her arrest. But the case was allowed to proceed after Sudan's foreign ministry advised the court that Hussein was not immune from prosecution.
