Lawyers for a woman who was stripped of her British citizenship after travelling to join the Islamic State group in Syria challenged the decision on Monday, arguing she was a victim of child trafficking.
Shamima Begum is one of hundreds of Europeans whose fate following the 2019 collapse of the Islamist extremists' self-styled caliphate has proved a thorny issue for governments.
Begum, then 15, left her home in east London in 2015 with two school friends to travel to Syria, where she married an IS fighter and had three children, none of whom survived.
She was later "found" by British journalists, heavily pregnant in a Syrian camp in February 2019 -- and her apparent lack of remorse in initial interviews drew outrage.
Dubbed an "IS bride", she was stripped of her British citizenship, leaving her stranded and stateless in Syria's Kurdish-run Roj camp.
Monday's hearing at the Special Immigration Appeals Commission (SIAC) follows a Supreme Court decision last year to refuse her permission to enter the UK to fight her citizenship case against the Home Office, or interior ministry.
Begum's lawyer, Samantha Knights, told the court that "at its heart this case concerns a British child aged 15 who was... influenced... with her friends... by a determined and effective Isis propaganda machine".
There was "overwhelming" evidence she had been "recruited, transported, transferred, harboured and received in Syria for the purposes of 'sexual exploitation' and 'marriage' to an adult male".
But she said the process by which the Home Office took the decision to remove Begum's citizenship was "extraordinary" and "over hasty" and failed to investigate and determine whether she was "a child victim of trafficking".
'Canadian spy'
A book published earlier this year by journalist Richard Kerbaj alleged that Begum, now 23, and her friends were taken into Syria by a Syrian man who was leaking information to the Canadian security services.
Mohammed Al-Rashed is alleged to have been in charge of the Turkish side of an extensive IS people smuggling network.
"It is now fairly well settled that she and her friends were transported across borders... by a Canadian asset of the Canadian security forces," Begum's lawyer Tasnime Akunjee told AFP before the hearing.
"The very definition of trafficking is pretty well established by that," he added.
Despite her initial comments, Begum has since expressed remorse for her actions and sympathy for IS victims.
In a documentary last year, she said that on arrival in Syria she quickly realised IS were "trapping people" to boost the caliphate's numbers and "look good for the (propaganda) videos".
Some 900 people are estimated to have travelled from Britain to Syria and Iraq to join IS. Of those, around 150 are believed to have been stripped of their citizenship.
Human rights group Reprieve told AFP there were currently 20-25 British families, including 36 children, still in camps in Kurdish-controlled northeast Syria, where suspected relatives of IS fighters have been held.
Other European nations have also been grappling with how to handle the return of their own nationals.
Hostile public opinion
Some countries, such as Germany and Belgium, have tried to carry out regular repatriation operations.
Last month, Berlin said it had settled "almost all known cases" of German families in jihadist prison camps in Syria, claiming to have repatriated 76 minors as well as 26 women.
According to Belgium's federal prosecutor's office, in mid-2022 there remained "a few women and a few children" in the Syrian camps.
Faced with hostile public opinion, however, France had carried out repatriations on a case-by-case basis.
But it picked up the pace in recent months after criticism from the European Court of Human Rights.
Since July, Paris has repatriated 31 women and 75 children in two operations.
Some 175 French children and 69 women are believed to still be in the camps.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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