An Iraqi Christian mother in her 30s who fled the Islamic State (ISIS) stronghold of Mosul has revealed the horrors she endured in the hands of the terror group, saying she was "married and divorced" as many as nine times a night only to give her tormentors a twisted justification for rape.

"They had me whenever they would desire it. Especially this one, Farouk, who was obsessed with me and he would say, 'I like the people of Jesus,'' the woman said in an interview with the non-profit group In Defense of Christians (IDC), who shared the video with Fox News.

She said the rapes were preceded by phony marriage ceremonies which the Islamic radicals believed gave them the permission to attack her.

Parts of the interview footage shows the woman crying and shaking from the torment she endured during her ISIS captivity, reports Fox News.

"What wedding? For them it was a wedding, but what kind of wedding is this?" she asked.

According to the woman, her husband disappeared after the terrorist group took over Mosul in 2014. She then left her two older children in the care of neighbours and went on to search for her husband.

"People were leaving, everyone was leaving, I mean, even the Muslims were leaving. But I didn't have anybody and I had hope in my husband and I said to myself, 'If I left, where would I go?'' she said.

Having no idea where to go, the woman said she decided to stay but unluckily she was captured by ISIS fighters who confronted and discovered her crucifix tattoo on her arms.

The ISIS militants reportedly took her and her baby to a school that had been converted into a slavery camp where she was repeatedly assaulted.

The report says the Iraqi Christian was able to escape because an ISIS fighter in the "school of death" was from her Mosul neighbourhood who recognised her and allowed her to slip away.

IDC President Toufic Baaklini said the woman's story is not uncommon and that many Christians and Yazidis experienced various forms of torture under the hands of the ISIS.

While commending the U.S. decision earlier this year to officially designate the plight of Christians in Iraq as genocide, Baaklini said there is a need to create a "safe haven" for them similar to the way the U.S. and NATO sought to protect Muslims in the 1990s during the Bosnian war.

"They just want to live in peace and pray and be free, so the safe haven, a secured area would be the next step for us to help them go back to their homes," Baaklini said.

The advocacy group meanwhile released a document that shows a price list for slaves, with the highest prices demanded for children between the ages of 1 and 9. Outside experts have reviewed the documents and judged it to be "consistent'' with the groups' brutal tactics, reports Fox News.

The document reportedly refers to women and children as "merchandise" and "spoils of war'' and that prices are "mandatory.'' A customer cannot purchase more than three spoils, except for foreigners like Turks, Syrians and Gulf Arabs. Violators of the price controls will be executed.

Outside experts also say the terror group sells women and children as house servants and for manual labour, says Fox News.