Canadian Prime Minister Justin Trudeau claimed that he will further investigate child trafficking allegations raised against a spy working for Ottawa's intelligence services, which say the spy trafficked British school girls into the hands of ISIS in Syria.

At least one of the victims of the child trafficking crimes covered up by the Canadian police and the British security services, Shamima Begum, 15, was married to an ISIS militant in Syria.

Begum, along with her schoolmates, Kadiza Sultana, 16, and Amira Abase, 15, met with a man called Mohammad Al-Rashed in Istanbul, Turkey, before heading to Syria. The British police launched an international search for the three girls at the time.

Rashed served as an informant for the Canadian intelligence, and the body told the Met police that he was linked to them in March 2015, just days after Begum went into Syria to join the ranks of the terrorist organization.

Trudeau defended Ottawa's actions, as customary, saying that intelligence services needed to be "flexible and creative in their approaches … in their work to keep Canada and Canadians safe in a very dangerous world."

The Canadian Security Intelligence Service (CSIS), Trudeau said, must abide by Canadian law despite its need for "out-of-the-box thinking". "We expect those rules to be followed," Trudeau underlined. "I know there are questions about certain incidents or operations of the past and we will ensure to follow up on those."

"We will continue to ensure that proper oversight is done and as necessary, look at further steps," the Canadian prime minister added.

The claims against the CSIS were made by Richarch Kerbaj, author of The Secret History of Five Eyes, a book published on Thursday delving into the intelligence network between the United Kingdom, the United States, Canada, Australia, and New Zealand.

According to Kerbaj, two CSIS officials met with the head of the Met's counterterrorism department, Richard Walton, in 2015, not too long after Begum disappeared.

The Metropolitan police were conducting thorough searches for the girls, two of whom are dead now.

After then-Home Secretary Sajid Javid revoked Begum's citizenship in 2019, saying she had aligned with ISIS and constituted a danger to the British public, her family's lawyer argued that she was a victim and was trafficked out of the country. The allegations raised against the UK and Canada, suggesting their involvement in her trafficking, could potentially cause a debate over whether she truly deserved to be stripped of her citizenship.

Begum is now 23 years old and lives in a detention camp in northern Syria. She has given birth to three children, all of whom died at a very young age.

Eight women repatriated to France from camps and prisons for militants in Syria were charged with criminal terrorist association in Paris, a judicial source said in early July.

Several women have been accused of abandoning minors, the same source said, while an 18-year-old teenager charged with the same crime has been placed under judicial control.

The International Committee of the Red Cross (ICRC) revealed a year ago that hundreds of children were incarcerated in prisons for adults in Northeast Syria.

These children, most of which are boys, were transferred from Al-Hol, a desert camp run by Syrian Kurdish militias for 60,000 people from more than 60 countries, due to their ties to ISIS militants.

Ahead of the latest repatriation came the detention of 120 women, and almost 290 minors were detained in Syrian camps controlled by Kurdish militias.