Human rights activists are calling for a change to Mauritanian law so that women and girls who have been raped will not be prosecuted for sexual relations outside marriage.

Rape survivors are reluctant to file complaints in the west African country in case they are then charged, according to a report by Human Rights Watch (HRW).

Adultery is known as “zina” and, in theory, is punishable by flogging, jail terms, or death by stoning if the offender is married or divorced. Mauritania does not as a rule carry out corporal punishments, so flogging and death by stoning can transmute into being imprisoned indefinitely.

One case cited by HRW involved a 15-year-old girl who was imprisoned after being repeatedly gang-raped by four men who held her captive for two weeks, because one of the men – whom she knew – said he would marry her.

In another case, a prosecutor was reported as asking a rape survivor: “If you didn’t consent, why didn’t you tell your parents?” When the survivor said she knew the man who raped her, the prosecutor said: “All the things you are saying are lies, you did this willingly.”

Government statistics are not freely available, so it is impossible to know how many people are in jail for zina, but girls as well as adults are thought to have been imprisoned for the “offence”.

“Women and girls should not run the risk of jail or further stigma for reporting sexual abuse,” said HRW’s Sarah Leah Whitson. “To combat sexual violence, Mauritania should require law enforcement and public health systems to stop treating victims as suspects, support them in seeking justice and recovery, and prosecute the perpetrators.”

HRW called for the government to decriminalise and stop prosecuting and detaining people for zina, as well as to pass a law defining rape and criminalising all other forms of sexual violence.

The Mauritanian government responded at length to the report, saying that most incidents of sexual assault and domestic violence were against minors or adolescents. “Perpetrators are often individuals close to the victims or family members who exploit the innocence and immaturity of the above mentioned people to sexually abuse them,” the government statement said.

Life is not easy for many Mauritanian women and girls. The prevalence of female genital mutilation is 67%, some ethnic groups see domestic violence as a sign that a husband loves his wife, and many girls are sent away to “fat camps” in the desert to be force-fed, so that they put on large amounts of weight and fit Mauritanian notions of beauty.