A former slave who was released from bondage in 2008 is to stand in September's parliamentary elections, the anti-slavery group IRA-Mauritania says.

Habi Mint Rabah hopes to be elected as an MP for the recently formed IRA/Sawab coalition - which is comprised of IRA-Mauritania and the more established Sawab party.

"I became a slave at the age of five. Every day I had to take care of the cattle. Every night I was raped by my master," Ms Rabah said shortly after her release.

"I always thought, without really understanding, that it was normal."

Slavery was outlawed in Mauritania but remains widespread, according to human rights groups. Black people of certain ethnic groups are often enslaved as domestic workers by lighter-skinned Mauritanians.

Convictions are rare, and the country has jailed more anti-slavery activists than slave owners, rights groups say.

Habi Mint Rabah was saved thanks to her brother Bilal Ould Rabah, who had managed to free himself. He alerted human rights organisations and the IRA movement, whose mobilisation resulted in the release of his sister after more than 35 years in bondage.

"She is a victim of slavery who we freed. She joined us, is militant, and will prove herself against the dominant pro-slavery group in the coming parliament," says IRA's President Biram Dah Abeid.