Police should have helped Shamima Begum return to Britain after she joined Islamic State in Syria because there were grounds to suspect she had been groomed as a child bride, a court has heard. Samantha Knights KC told a tribunal that the police had an obligation to investigate whether Begum, who was 15 when she left the UK, was a victim of human trafficking, and then help her return if she was. At the second day of a hearing of the Special Immigration Appeals Commission (Siac), Knights said children “cannot consent to their own exploitation”. She told the hearing: “Children allegedly associated or affiliated with terrorist groups are often, in fact, victims of terrorism and trafficking.” Knights said the government had an obligation to prevent trafficking, identify perpetrators, assist victims and help them return home. Begum, now 23, left her home in east London in 2015 while a GCSE student at Bethnal Green academy. She married an IS soldier from the Netherlands within days of her arrival and had three children, none of whom survived. She was stripped of her British citizenship on the grounds of national security in February 2019 by the then home secretary, Sajid Javid. The government’s modern slavery strategy, introduced in November 2014, imposed the obligation to pursue perpetrators, prevent engagement in slavery or exploitation, and improve the identification of victims. “Children cannot consent to being trafficked, nor can they consent to child marriage,” Knights said. Under international law, a child marriage occurs where at least one party is under 18 and is considered forced marriage, Knights told the hearing. Article 4 of the European convention of human rights imposes an operational duty to help victims of trafficking and assist their rescue and recovery, the court heard. Knights said: “It is unarguable that there was a credible suspicion that Miss Begum was the subject of trafficking and there therefore was an obligation to investigate whether she was the victim of trafficking from the UK and what they could do in terms of recovery.” She added: “In this case we say there were missed opportunities by the school and the police.” No consideration was given by Javid to the “obvious importance” of the rescue, recovery and rehabilitation of Begum as a child victim of trafficking, her lawyers said. On 10 December 2014, two months before she left for Syria, an assessment conducted by Bethnal Green academy said Begum was “at risk of radicalisation”, the court heard. It was noted that “she was close friends” with Sharmeena Begum, who had gone to Syria after leaving school. Police gave Shamima Begum and her friends a letter about the “disappearance” of Sharmeena Begum, and asked them to deliver it to their parents. Knights said: “The letters were not delivered and at no stage, it appears, were the families ever told that Sharmeena had travelled to Syria or that there were any concerns about the appellant and her friends.”