A former slave is suing the state of Niger in a landmark legal challenge, claiming that the country failed to protect her from being sold into a life of servitude and sexual slavery.

Hadijatou Mani accused the Government yesterday of failing to implement its own laws that criminalised slavery in 2003.

If successful, her case — which is being heard by the Community Court of Justice of the Economic Community of West African States (Ecowas) — could pave the way for similar claims from the hidden population of slaves living in their hundreds of thousands across the Sahel region.

“I want people to know what is happening,” said Ms Mani, who was sold to a master for £250 when she was 12 years old. Giving evidence with her youngest child strapped to her back, the former slave told the court how she was bargained over “like a goat”.

She said: “I have not had a day off in my life, and I want the suffering of so many women to stop. This situation must end, so I am very pleased I have been able to tell the judges about my case.” She is claiming compensation of about £40,000 and hopes that a judgment will strengthen legislation in Niger, where anti-slavery laws appear to have made little impact since being introduced five years ago.

The case is unique because it is the first of its kind to be heard by the Ecowas court. A ruling in her favour would oblige all 15 West African member states to take action against slavery, a traditionally acceptable practice that remains taboo and whose existence is often still denied at official levels. “This is a hugely significant case,” said Helen Duffy, legal director of Interights, a non-governmental organisation based in London that is sponsoring Ms Mani's case.

“It should clarify not only Niger's obligations to protect people like Hadijatou, but also those of many other countries. The actual process itself is having a positive impact, and already we are seeing debate on a subject which some governments still claim doesn't even exist.”

Romana Cacchioli, of Anti-Slavery International, which is also supporting the case, said: “A positive ruling would send a message that the longstanding legal prohibition on slavery must be translated into practice.”

About 43,000 people are thought to be enslaved in the impoverished desert nation of Niger. For ten years, Ms Mani was forced to carry out unpaid domestic and agricultural work, and was later abused as a sexual slave by her owner, who had four wives and seven other such slaves, or “sadaka”. When Niger outlawed slavery, Ms Mani was released officially and given a “liberation certificate”. Her “master” refused to let her go, claiming that she was his wife, but a local tribunal allowed her to leave.

However, when she married another man, she was found guilty of bigamy and was forced to spend three months in jail.

Ms Mani, who is thought to be 24, is the first former slave to bring an action against a state. In the past, members of slave castes in countries such as India have mounted legal challenges against individuals or former employers.

Her lawyers argue that slavery is still accepted in customary law, despite being outlawed by Niger's criminal code and constitution.

Yesterday, at the Supreme Court in the capital of Niamey, where Ecowas is sitting, state representatives denied that slavery was a problem.

The sociologist Djouilde Laya disputed the claim, telling the court: “There are two important dates in the history of this country. One is the day of independence. The other is the day this case began.”

The trial is expected to last five days.

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