ISIS has executed 19 women for refusing to practice 'sexual jihad', a Kurdish official has claimed.
He told an Iraqi news website that women were being held in the terror group's stronghold of Mosul in Iraq.
The official also said there have been recent splits in the ranks of ISIS because of arguments over money and the way captured women are distributed.
On top of this, a UN envoy investigating sexual violent in the conflict has confirmed that an ISIS pamphlet that gives prices for the purchase of women is real.
Zainab Bangura told Bloomberg that “the girls get peddled like barrels of petrol”.
“One girl can be sold and bought by five or six different men. Sometimes these fighters sell the girls back to their families for thousands of dollars of ransom.”
ISIS abducted hundreds of Yazidi women last year when they stormed northern Iraq.
The Yazidis are a Kurdish religious group that ISIS considers heretics.
Disturbing reports of women and young girls being sold into sexual slavery, with the youngest fetching the highest price, have been confirmed in a number of reports.
Ms Bangura states that prices for boys and girls aged one to nine are about $165.
Adolescent girls cost about $124 and it's less for women over 20.
“They have a machinery, they have a program,” she told Bloomberg.
“They have a manual on how you treat these women."
Last month, three Yazidi women who escaped ISIS spoke of the horror they experienced at the hands of the terrorist group.
One woman, Bushra (21), said she was raped repeatedly by the man who bought her.
"He told me he was going to rape me that same day, however ill I made myself. He took me home, tied up my hands and feet, and raped me," she said in a video.
"He raped me about five times a day. My sister was barely 14 when they raped her.
"'I could hear her screaming but I couldn't do anything as I was tied up," she said.
Amnesty International previously said that ISIS have destroyed hundreds of Yazidi women's lives
Donatella Rovera, Amnesty International’s Senior Crisis Response Advisor, spoke to 40 Yazidi women who had managed to escape last year, and said that what ISIS had done to them amounted to war crimes.
“Hundreds of Yezidi women and girls have had their lives shattered by the horrors of sexual violence and sexual slavery in IS captivity,” she said.
It's been one year since Isil militants targeted ethnic Iraqi Yazidis in Sinjar Province in northern Iraq, triggering a reluctant return to US military strikes in Iraq by the Obama administration. Twelve months later and the deeply disturbing plight of young Yazidi girls kidnapped and raped by the Islamist terrorists is still unfolding.