Shamima Begum was smuggled into Syria for Islamic State by a Canadian spy whose role was covered up by security services, it has been claimed.
Ottawa is accused of withholding information about her whereabouts while the Metropolitan police scrambled an international search for her.
However, it is stated that Canadian intelligence did not learn that Begum had been recruited until four days after she left Britain, when she had already crossed the border into Syria.
Begum was a 15-year-old schoolgirl when she and two fellow pupils at Bethnal Green academy travelled from east London to Syria in 2015.
She, along with her schoolfriends Kadiza Sultana, 16, and Amira Abase, 15, were met at Istanbul bus station for their onward journey to a life with IS in Syria by a man called Mohammed Al Rashed.
The claim is made in The Secret History of the Five Eyes by Richard Kerbaj, which is published on Thursday. Five Eyes is the network of intelligence-sharing between Britain, the US, Canada, Australia and New Zealand.
Rashed is said to have been a double agent who shared Begum’s passport details with Canada and smuggled dozens of others from Britain to fight for IS.
The Begum family’s lawyer, Tasnime Akunjee, argues that the teenager was trafficked out of the country. The suggestion that a western intelligence asset may have been involved, including organising bus tickets for the schoolgirl, will reignite the debate over the removal of her British citizenship.
The Met police are said to have been informed about the role of a Canadian double agent in smuggling the girls out of Britain.
In the book, Kerbaj writes that Canada’s intelligence service “remained silent about the explosive allegations, taking refuge in the one thing that protects all intelligence agencies, including those within the Five Eyes, against potential embarrassment: secrecy”.
“For seven years now this has been covered up by the Canadians,” Kerbaj told the Guardian. He said he interviewed multiple Canadian intelligence officials for the book, who confirmed the timeline of events.
“I think the cover-up is worse than the offence in many ways here because you would expect human intelligence agencies to recruit members of criminal groups and terrorist groups.”
Kerbaj said British authorities also failed to be open once they learned of Rashed’s role for Canada in recruiting the girls.
“I think they felt on balance that it’s best not to discuss this because there were still British and other western hostages in Isis territory,” Kerbaj said.
“There was concern that at the same time that they’re trying to get access to Isis and trying to infiltrate Isis, if a story like this emerges that one of their own had been flipped there, was working for the Canadian services, then that would potentially make them even more paranoid and start beheading people.”
Last year, the supreme court upheld a 2019 decision to bar the now 23-year-old from returning to the UK. Begum lives in a detention camp in northern Syria, having given birth to three children, all of whom died young.
There was no suggestion in the supreme court judgment that the British authorities knew the circumstances of her smuggling into Syria.
Begum is due to make a fresh case at the special immigration appeals commission in November. _Agencies