Islamic State has issued harrowing guidelines for how its militants are to treat their female slaves.

Dated October/November 2014, a Q&A leaflet details exactly how IS followers are to buy, sell and abuse "unbelieving" women – thought to mean all those who are not Sunni Muslims.

"What makes al-sabi permissible [ie what makes it permissible to take such a woman captive] is [her] unbelief. Unbelieving [women] who were captured and brought into the abode of Islam are permissible to us, after the imam distributes them," the pamphlet prescribes, according to an English translation.

"It is permissible to have sexual intercourse with the female captive," it continues. "Allah the almighty said: [Successful are the believers] who guard their chastity, except from their wives or (the captives and slaves) that their right hands possess, for then they are free from blame [Qur'an 23:5-6]."

According to the document, female captives are "merely property, which can be disposed of" – ie bought, sold or given away. A man is free to have sex with a virgin female slave as soon as he buys her, though a woman who is not a virgin must have her uterus "purified" first.

Disturbingly, the pamphlet instructs that "It is permissible to have intercourse with the female slave who hasn't reached puberty if she is fit for intercourse; however if she is not fit for intercourse, then it is enough to enjoy her without intercourse."

The document also clarifies that disciplinary beatings are permitted, though "beating for the purpose of achieving gratification" and torture are not.

Any female slave who attempts to run away is to be "reprimanded in a way that deters others like her from escaping," it adds.

Islamic State has admitted to selling women to their fighters and justified the practice with early Islamic teachings. The group is thought to have kidnapped thousands of women this year.

A document obtained by IraqiNews.com last month revealed that Yazidi and Christian women are being sold for as little as £27.

A price list said that those between 40 and 50 years old will fetch 50,000 dinars, or around £27.

The price of a slave increases as they get younger; a girl between 10 and 20 years old will sell for about £80, while those between the ages of one and nine are sold for just over £100.

A video also recently emerged apparently showing IS fighters discussing the price of Yazidi women and girls during a "slave market day" in Mosul.

"Today is distribution day, God willing. Each one takes his share," a man says to the camera.

Several men are seen bartering over the women, with one offering a pistol in exchange for a girl, while another says the price is dependent on "how she looks".

Charlie Winter, a researcher for Quilliam, a counter-extremism think tank, has denounced the latest IS guidelines as "abhorrent".

"The roots of this document can easily be traced back to some of Islamic State's most active propagandists, something that leaves little doubt in my mind about its credibility," he told The Independent.

"The content, while it is abhorrent and shocking, is not surprising – we know that IS ideologues have justified and legitimated slavery in past publications."