She crossed into Turkey six weeks ago and lives in constant fear that ISIS militants will hunt her down and kill her

Leena says foreign fighters as brave at first but realised they were only after 'money, gold and slaves'

There are five British girls in ISIS's Hisbah religious police and foreigner jihadis are given preferential treatment, she claims

ISIS leader Abu Bakr al-Baghdadi personally sanctioned a woman to be beheaded as a wedding present for a sadistic female 'judge' in the terror group's feared religious police, MailOnline can reveal.

The notoriously cruel woman asked to kill an unbelieving 'infidel' in return for taking a new husband following the death of her mujahedeen husband in a battle.

But al-Baghdadi insisted she could only take the life of another woman in line with the group's strict segregation of affairs between men and women. He ruled she could cut off the head of another female ISIS judge who had been accused of spying - but who in reality had probably just fallen out of favour.

Scroll down for video

Afraid: Leena (pictured), whose name has been changed, defected from ISIS after the female Sharia court judge she worked for was beheaded in a twisted 'power struggle' with another judge

Haunting: Leena has exposed the dark reality of living under ISIS rule and how 'innocent' people were executed and women were brutally lashed in public 'by mistake'

This barbaric gift is just one of series of shocking claims made by a female defector from ISIS' religious police, Hisbah - which rules the so-called Islamic State of around eight million people - with its own twisted and medieval interpretation of Sharia law.

During the harrowing interview, Leena - not her real name - gave an unparalleled insight into how the Islamic State is run.

She described the suffocating effect fear has in a society where children are used as informers, how one woman was given 80 lashes in public by 'mistake', the corrupt power struggle that led to her boss having her head chopped off, and the terrible treatment of Yazidi prisoners – given to ISIS fighters as sex slaves 'to do with whatever they like'.

Leena revealed how there are five British women in the Hisbah, including converts, who are apparently given preferential treatment by the ISIS leaders. Among them was a blonde woman called Susanne and a red head called Fatima.

The ISIS defector told MailOnline: 'When the foreign fighters and women first arrived we thought they were heroes. They had come to give their lives to fight for us, to fight for our freedom.'

But it soon became clear that they came for whatever 'money, gold and slaves' they could get. Leena branded them nothing more than rapists, looters and thieves.

As just one example of the horrors she saw on a daily basis, the 27-year-old mother-of-two told how a local girl was sentenced to death after the Hisbah discovered she had complained about life under ISIS in a WhatsApp message to her sister in Damascus.

Brainwashed: Leena (pictured) admits that she was won over by ISIS' hardline brand of Islam at first, but the horrors and injustices that she witnessed forced her to flee from the 'Caliphate' with her family

Turning point: Leena believes ISIS leader Abu Bakr Al-Baghdadi (pictured) sanctioned the killing of Um Abdullah al-Saud, the Sharia judge she worked for as an administrative clerk, as a wedding present

In sad, hushed tones, Leena said: 'It was nothing more than murder. They said she was connected to Assad's regime, a spy.

'She wasn't receiving her salary and she could not travel to collect it. All she wrote in the text was "We are all under pressure", "We can't go on", "We are in trouble".

Because of that the judge, originally from Egypt, gave her the death penalty. They said she was a spy for the Assad regime.'The girl had been telling the truth. Despite the vast oil deposits nearby the town's only electricity comes from diesel generators – controlled by senior ISIS members, called emirs. Air-conditioning can no longer offer families relief from the 50C summer heat. Water supply is erratic at best.Now in hiding and facing a life on the run, wide-eyed with fear, Leena said: 'I was horrified by what I saw, the brutality and corruption. I left because I saw so many terrible things, so much destruction, beatings.'

Recently married and pregnant with her first child, Leena fled from fighting in Deir Ezzor, once a prosperous provincial town on the banks of the Euphrates River and now the centre of Syria's oil industry, in September 2012, to a neighbouring village which became the ISIS regional HQ.

'All we knew was we had to pray five times day and fast during Ramadan', said Leena. 'Before no one wore a niqab (face veil), we did not wear Islamic clothing and there was no rules about talking with strangers - men who were not close family members.'

Leena freely admits that at first she fell for ISIS' hardline brand of Islam which they romantically painted as the true path for a Muslim.

Her community, like the majority of Syria and ISIS follow the Sunni branch of Islam and consider Syrian president Bashar al-Assad as a heretic because he is a member of the Alawites, an obscure sect within the rival Shia vision of Islam.

Leena became inspired to learn more about Sharia Law and completed an ISIS indoctrination programme.

'We went around other villages to help people understand Sharia Law, to show them the way to follow Islam,' she said.

Terror: The role she performed was not dissimilar to that of ISIS's all-female police force, the Al-Khansaa Brigade (pictured), who enforce strict Sharia law on the streets of Islamic State's adopted capital Raqqa

Promotion: As a reward for her work as a spy, Leena was offered a job working as a 'writer' for a Hisbah judge in the town of El Mayadin, near Deir Ezzor

As more foreign fighters flooded into the area, families gave up daughters and widows as brides to the arriving 'heroes'.

'My husband had joined the fighters. My friend explained I would get a salary of $200 a month and I could stay with my parents,' explained Leena.

Smiling as she recalled her innocence, she described how she ended up joining the Hisbah in May 2013.

I did the training many times, looking for unbelievers. I would listen to what they [the recruits] said and report them if they said they did not like ISIS

'I gave 'bayah' [an Islamic oath of allegiance], I joined ISIS, working for the Hisbah in the section that dealt with women. Their job is to uphold Sharia Law – to make sure women wear the niqab [face veil], wear the correct clothes and behave in the correct way with men.'

Her first mission was to infiltrate a Sharia training camp and spy on young women forced to adopt the strict Islamic code.

'I did the training many times, looking for unbelievers. I would listen to what they [the recruits] said and report them if they said they did not like ISIS,' she said.

The women who she informed on would be sent to the Sharia Court where they would be tried and faced punishment beatings. Leena would not be drawn on whether she felt responsible for the pain and suffering she inflicted on other mothers, sisters and daughters.

In return for her loyalty, she was offered a job working as a 'writer' for a Hisbah judge, a position similar to working as a clerk to an investigating magistrate - taking down statements from suspects, witnesses officers of ISIS' religious police force, in the town of El Mayadin, near Deir Ezzor.

She worked for a female judge who ruled only on crimes committed by women in a Sharia court separate from that which would judge men for their alleged offences.

With salaries no longer being paid by the Assad regime, the $200-a-month offered by ISIS provided a lifeline.

War-torn: El Mayadin (pictured in April) has been ravaged by constant fighting with the Syrian regime which has reportedly attacked the town with car bombs

Gruesome: In January, ISIS released images from the embattled town of El Mayadin where it claimed to kill and mutilate 11 civilians (pictured) for 'apostasy' - or abandonment of Islam

Punishments to the 'guilty' included fines for wearing 'non-Islamic' clothing, whippings or beating for 'inappropriate' association with men, chopping off hands for stealing, death by stoning for adultery and beheadings for treason.

However, she soon began to see terrible miscarriages of justice.

'People have been condemned to death even when they are innocent. A woman was arrested for talking to a man in a shop. She explained that the man was her husband but the Hisbah officer did not believe her.

A woman was arrested for talking to a man in a shop and she said it was her husband. She was whipped like an animal - 80 lashes, in the main square in front of everyone. Later, she proved they were married

'She was brought before an Egyptian judge, a monster, a devil. She sentenced the Syrian woman to a terrible beating. She was whipped like an animal – 80 lashes, in the main square in front of everyone.

'Then the man turned up with his marriage contract and proved that she was his wife. But it was too late.'

She added: 'The Egyptians and the Tunisians were nothing better than thieves. They did not care if someone was guilty or not, they would start to beat them before the judge had investigated their crime.'

The more zealous and vicious members of Hisbah would volunteer to carry out the punishments, usually in public to act as a graphic deterrent to the oppressed residents.

Leena claimed that she never took part in the floggings.

In the two years that Leena worked for the Sharia Court, countless whippings and beatings were doled out. She also said there were three amputations and one beheading that took place in the main square – all in a town of less than 85,000.

Other beheadings followed after she fled.

Leena said: 'If there was a public beheading or amputation in the main square, I could not watch. I would see the head or the limb lying on the ground later, but I did not want to watch.'

During the four-hour conversation, the Muslim call to prayer echoed across the town in Southern Turkey where Leena had agreed to meet.

Brutal: Leena says three amputations (pictured) took place in the main square of El Mayadin during her time working for the Sharia court. It is usually a punishment ISIS doles out to people suspected of theft

Execution: One beheading took place in El Mayadin (file photo) during her time in the town, and others apparently happened after she escaped six weeks ago

Punishment: Leena claimed that she never took part in the floggings (pictured in Iraq) in the public square but she saw enough brutality in El Mayadin to convince her she needed to escape

It had taken intermediaries many days to convince her to open up and tell the truth about life under ISIS.

Dressed conservatively in a long black Islamic robe and with a light brown head scarf she arrived at the agreed location trembling with fear.

After several hours she opened up – offering a glimpse of what this once happy woman had to witness living in the ruthless shadow of ISIS.

The defector worked for a number of different judges but it was the fate of her boss – Um Abdullah al-Saud – that helped convinced her that she must abandon ISIS.

There was another judge, a Tunisian, Roaa Um Khotaba al-Tunisi, she was a real monster... For her wedding present she asked the emirs to cut off the head of a kuffar, an unbeliever

'Um Abdullah was married with four children. She was kind,' Leena said.

'If the woman brought to her was poor she would give her a very small fine. One time she had to sentence a woman to a beating, so she beat the woman with her pencil so it would not hurt but still be within the law.

'But there was another judge, a Tunisian, Roaa Um Khotaba al-Tunisi, she was a real monster. She was married to a Libyan fighter and he was killed in battle in Kobane. The ISIS leaders said she should marry again because she was young, maybe 30.

'For her wedding present she asked the emirs to cut off the head of a kuffar, an unbeliever. Her request went to the top of ISIS, Abu Bakr al-Baghdadi, who considered it for a long time.

'Finally he said she could have a prisoner beheaded, but it had to be a woman. At about the same time my judge, Um Abdullah, disappeared. She had been accused of being a spy, working for the Saudi Intelligence Services. She was captured and taken to jail.

'The Tunisian, Roaa Um Khotaba Al-Tunisi, asked for head of Um Abdullah and she was sentenced to death.

'When I asked others in Hisbah what she had done I was told not to ask, for my own safety.'

Leena is too frightened to say it but MailOnline understands that Um Abdullah is not a spy. She had been the victim of a power struggle within the Hisbah leadership in El Mayadin, which the the Tunisian 'devil' had won.

Armed: Leena told of how a woman was arrested by ISIS deadly Hisbah religious police (pictured in Iraq in 2014) because she touched a man's hand in a shop. The woman was sentenced to 80 lashes in public square

Force: In September last year, ISIS released terrifying images of its Hisbah religious police force standing guard outside an Islamic State prison in Iraq's Nineveh province (pictured)

Children became involved and corrupted by the strict laws and vicious punishments of the Hisbah – acting as informers.

Some of the Hisbah patrols had children as informers, children as young as eight,' Leena said. 'They would be paid to spy on other children.

'There were children on the checkpoints – working with their fathers. The head of the street patrols was only aged 19.'

She explained: 'One time a girl was accused of dressing inappropriately. She was tall but her mother said she was only nine-years-old. She brought her birth certificate to the court to prove it.

There were many foreigners in Hisbah... They all had Islamic names but two of them told me their old names, their Christian names - Maria and Susanne... Maria was blonde and about 30-years-old.

'The child informers thought they would get credit from ISIS for accusing the girl of breaking the Sharia Law about dress – even though she was only a child. Fortunately the judge – my judge Um Abdullah – spared her and let her go.'

Leena revealed the privileged position Muslim converts held within the Hisbah structure, particularly five young British women she came across. They would travel the 'Caliphate' with senior ISIS leaders and were allowed to carry guns.

'There were many foreigners in Hisbah – women from Iraq, Libya, Tunisia, Algeria and Egypt and from Europe,' she said.

'There was a woman from Norway, one from Germany, a lot from France and five women from Britain.

'Two of the British women spoke Arabic but not very well, and the other three could only say greetings – they were all Muslim converts.

'They would criticise Syrians saying "you can't do that" even though they had only been Muslims for three or four years.

'They all had Islamic names but two of them told me their old names, their Christian names - Maria and Susanne. Maria was blonde and about 30-years-old.

'Susanne was very beautiful her hair was between blonde and brown. I think she was a nurse because she had been treating injured fighters on the front line.

Terrified: Leena spoke to MailOnline in a town in southern Turkey (pictured) where she is on the run from ISIS

'And then there was Aisha, who was blonde, Fatima who was a redhead, she knew about oil and I can't remember the other girl's name.'

She added: 'They were with the emirs. They travelled around with them in their jeeps. They had been in Iraq and places in Syria for a few months at a time. They carried weapons with them, only foreigners are allowed to carry weapons.'

The Britons had been brought to El Mayadin to convert 'heretical' Yazidi prisoners who had been captured on Mount Sinjar in August last year, in one of the most shocking human tragedies of the Syrian conflict.

At first the foreign fighters were very brave. Now they are only interested in what they can get for themselves – money, gold, slaves

The Yazidis, who belong to a faith that has elements of both Christianity and Islam, were cornered by the advancing ISIS army as the world looked on helplessly. When ISIS over-ran their towns and villages they massacred thousands of men and boys and took the women and girls as slaves.

Leena said: 'The emirs had captured maybe 200 Yazidi women but by the time they brought them to us there was about 100. The others had been given away as slaves.

'The British tried to convince them to become Muslims. They told the Yazidis: "Why don't you convert your faith to Islam, don't be afraid. You will be happy as a Muslim".

'The Yazidis who converted to Islam were given to the emirs. They were treated better. The kuffar [infidels] were given to local fighters – to do with them whatever they wanted - sex, beating, death.'

Horrified by what she was seeing and hearing every day, Leena became increasingly disillusioned with the so-called Islamic State and tried to convince her husband that the young family had to leave.

Like his wife he had supported ISIS at first, as they battled against Assad's regime.

But he later found that the foreign fighters were no longer the 'heroes' they had been – prepared to die to defend the Syrian people – but rapists, looters and thieves.

Escape: The captured Yazidis (file photo from Mount Sinjar last year) 'were given to local fighters – to do with them whatever they wanted - sex, beating, death,' Leena claims

Leena said: 'At first the foreign fighters were very brave. Now they are only interested in what they can get for themselves – money, gold, slaves.

'They push local fighters into battle first and when they win territory they are most interested in stealing whatever they can.

'When a local man dies they say 'someone can now take his wife'.'

When Leena's boss Um Abdullah was sentenced to death the family knew they had to escape.

She said: 'You can imagine how frightened I felt because I was her writer [clerk]. I feared I would be next, be beheaded. I don't know if she is dead or alive but I fear the worst.

We couldn't bring our kids up under ISIS, letting them watch amputations and beheadings. When my oldest plays computer games he does not use a gun, he always uses a knife. I got him a song book, but he said: 'I don't want to sing, I want to fight'

'I had been telling my husband that I had enough of ISIS, but he did not want to listen. After seeing the looting he agreed. A few days later we left Syria.'

Using fake documents and disguised in old clothes and wearing full-face Islamic robes the family – including two children under five – fled El Mayadin.

Travelling by mini-bus they passed through the ISIS 'capital' Raqqa and into territory controlled by other rebel groups – relying on the compassion of their drivers and the militia soldiers to spare them.

They crossed the border into Turkey at the town of Kilis, six weeks ago.

Leena said: 'I had my children on my lap and I was frightened for them, but we had to leave Syria because of them.

'We could not bring our children up under ISIS – letting them watch amputations and beheadings. When my oldest plays computer games he does not use a gun he always uses a knife.

'I got him a song book, but he said; "I don't want to sing, I want to fight".'

Although they are out of Syria, and away from the fighting, Leena remains frightened.

In constant fear that ISIS agents will find them and exact some terrible punishment, they are on the run in southern Turkey – changing addresses every three or four days.

She said: 'Before the war I was a government administrator and my husband was a salesman. We married about one year before the revolution [in March 2011]. We had a nice house and a car, a Mazda.

Covert: Leena's (pictured) first mission was to spy on young women at a 'Sharia training camp' and find 'unbelievers' who would be sent to Sharia Courts where they would be tried and faced punishment

'My husband liked to go fishing and hunting rabbits. We were happy. Life now is difficult, it is not safe. I don't go out, except to buy provisions.