Dozens of infamous Brits who joined terror groups, including Jihadi Jack and Isis bride Shamima Begum, could escape from squalid camps and jails in Syria and return to the UK.
It follows the downfall of Syrias bloodthirsty tyrant, Bashar al-Assad, who was dramatically deposed after rebels seized the war-torn nations capital, Damascus.
Now, as the fallout from the takeover rages on, there are fears scores of Isis fighters caged in camps in northeast of Syria could take advantage of the chaos and escape.
It follows a warning by the former chief of Britains MI6, who said thousands of jihadis being held in Syria pose a chronic threat to the Wests security if they are released.
Sir Alex Younger said the toppling of the Assad regime risked a serious spike in the threat of a very large number of Islamic State (IS) detainees becoming free.
There are fears a flood of extremists could head to Europe if security around their detention camps is relaxed, with experts warning conditions in lock-ups of Kurdish-controlled northeast Syria were a perfect breeding ground for radicalisation.
Currently, the Kurdish forced guarding the jihadists are backed by US troops. However, its not clear whether this will be the case when Donald Trump returns to the White House next month.
Its believed around 70 Brits are being held. But human rights charity Reprieve said more than half of these were children, while some were victims of trafficking.
Jihadi Jack (pictured) is one of the Brits who went over to fight with Isis currently detained in a jail in Syria
Also trapped in Syria is British-born Isis bride Shamima Begum, who has been stripped of her British citizenship
Pictured is the squalid Kurdish-run al-Hol camp, which holds relatives of suspected Islamic State (IS) group fighters
Among those to have travelled from the UK to join Isis includes the notorious Jihadi Jack, whose real name is Jack Letts.
The 29-year-old left his Oxfordshire home in 2014 to join IS, having converted to Islam as a teen. He fought in Iraq but has claimed to have never killed anyone.
After being captured by Kurdish authorities in 2017, he begged to be allowed back to the UK, having previously declared himself an enemy of Britain.
Letts, originally from Canada, this month pleaded to be repatriated to his home country so he can rot in jail there instead of staying in a Syrian prison camp.
He gave a bombshell interview after being found by a television crew in a prison near Raqqa. It was the first time he has appeared on camera in five years.
Speaking to CTV News W5 programme, Letts denied he had ever been an IS member, but told how there were things he couldnt say as he was still behind bars.
He told W5s Avery Haines he would have no problem being taken back to Canada - even if it meant he had to spend 100 years in jail.
At least let me rot in a prison in Canada, Jihadi Jack said.
Jack Letts, 29, a Canadian originally from the UK who has been detained for seven-and-a-half years among suspected Islamic State members in northeastern Syria
The bombshell interview with CTV News W5 programme has now become the first time Letts has appeared on camera or been allowed to speak to media since 2019
Lettss mother, Sally Lane, 62, who has been calling for the Canadian government to repatriate all of its own citizens held in Syrian camps and jails, told Middle East Eye there seems to have been a clear deterioration in his condition in the past five years.
I was shocked at Jacks condition, and how distressed and clearly traumatised he is, said Lane. I am so angry at the Canadian and British governments that they think its okay to completely destroy him as a human being.
Jack is going to die if they dont repatriate him.
They know this, and still they do nothing.
Another British jihadist caged in Syria is disgraced pharmacist Mohammad Anwar Miah, from Birmingham.
He claimed to have travelled to Syria in 2014 to carry out humanitarian work and insisted he was never part of Isis.
Mohammed Anwar Miah, a pharmacist from Birmingham, is a suspected jihadi in a Kurdish prison in northern Syria
However, Syrian witnesses claimed the 45-year-old was part of a team of that removed organs from prisoners, which were later transplanted into wounded jihadist fighters or sold on the black market.
At one point Miah - thought to have renamed himself Abu Obayda al-Britani - was held alongside the so-called Beatles gang responsible for beheading Brit hostages.
Speaking to the Daily Mail in 2019, Miah claimed he never swore allegiance to the group and that he had worked there as an assistant orthopaedic surgeon in the IS-held town of Mayadin.
Miah, who has a Syrian wife and two children, said: I want to go home. Im proud to be British. Britain has got good human rights and that is a good thing.
Also feared to be among the terrorists who could one day escape from Syria is former Londoner, Shahan Choudhury, from Tower Hamlets.
The 37-year-old was radicalised by hate preacher Anjem Choudary during 18 months on remand in Belmarsh prison in south-east London.
Shahan Choudhury, pictured, was allegedly radicalised while on remand at Belmarsh Prison in London by hate preacher Anjem Choudary before fleeing to Syria
He became an Isis fighter after having initially travelled to Syria to carry out charity work. He was the last British Isis members to be captured in 2019 at the final battle for Baghouz.
Choudary - who has been stripped of his British citizenship and is locked up at the high-risk mens jail in Hasakah city - said he regrets his decision. I didnt know it would turn out this ugly, he told The Times earlier this year.
I would go back and serve my life in a British prison if they would let me. But they probably wont, so I would go anywhere. I just want to leave.
Choudarys wife, Mahak Sabrina Aslam, followed her husband from their home in London to Syria, arriving months after him.
She has also lost her British citizenship and currently lives in the disease-ridden al-Roj camp, where Shamima Begum is held.
Choudarys wife, Mahak Sabrina Aslam (pictured), followed her husband from their home in London to Syria
Aslam, whose eldest daughter was blown up in an explosion, lives in the hellhole detention centre with her four surviving children.
Jailed alongside Aslams terrorist husband in Hasakah is fellow British jihadi Ibrahim Ageed, from Leicester.
The 29-year-old former medical student has been rotting in the 4,000-man prison complex for more than five years.
Originally from Sudan, he travelled to Syria when he was 21 to volunteer as a medic, moving around several hospitals to treat Isis fighters.
Speaking last year, the jihadist argued he had the right to face the music and return to the UK to face justice.
He told The News Movement: I believe Ill be subjected to the justice system but Im ready to face the music and I believe its my right basically to go back home.
Ibrahim Ageed, pictured, a former medical student from Leicester, is one of two Britons being held in the north east of the country after being captured while fighting for Isis
Thousands of jihadis being held in Syria pose a chronic threat to the Wests security if they are released, the former chief of MI6 has warned. Pictured: A masked Islamic State soldier poses holding the ISIL banner somewhere in the deserts of Iraq or Syria
There are fears a flood of extremists could head to Europe if security around their detention camps is relaxed. Pictured: Men, suspected of being affiliated with the Islamic State (IS) group, in a prison cell in the northeastern Syrian city of Hasakeh
Meanwhile, the collapse of the Assad regime could present a new opportunity for Isis bride Shamima Begum, her lawyers have claimed.
The British-born 25-year-old was one of three schoolgirls to travel to Syria before going on to marry a jihadist, who she went on to have three children with.
Begum had her British citizenship revoked after moving to Syria in 2015 at the age of 15.
She has been battling since then to get it reinstated.
Begum lost an appeal last year against the decision to revoke her citizenship on national security grounds at the Special Immigration Appeals Commission.
In August, justices at the UKs highest court said Begum could not appeal again after she lost a Court of Appeal bid in February.
Begum is believed to be living at the Al Roj, a filthy, brutal temporary tent city teeming with dangerous Isis loyalists who use threats and beatings to enforce their extremist ideology.
Meanwhile, the collapse of the Assad regime could present a new opportunity for Isis bride Shamima Begum, her lawyers have claimed.
Begums lawyers believe if the camp is closed, she could launch a fresh claim on human rights grounds as her life would be at risk in the Syrian desert: Watch this space, Tasnime Akunjee said.
Al Roj is home to around 2,600 detainees from 55 countries, many of them Isis brides and their children.
One of those children trapped at the camp is 16-year-old Abdullah Hammad Ali.
He was brought to Syria by his British-Pakistani mother when he was just seven.
He claims he was too young to undergo military training with the terror group and said his peers at the camp all hate Isis and just want to forget and be normal children again.
Experts worry that western Syria could become a new Islamist state under Hayat Tahrir al-Sham (HTS), the former Al-Qaeda group that overthrew Assad after his 24-year rule.
Assad - branded the rat of Damascus by UK foreign secretary, David Lammy - escaped Syria by private jet with his British-born wife Asma and their children.
He has now been given asylum in Moscow by close ally and fellow despot, Vladimir Putin on humanitarian grounds, the Kremlin confirmed this week.