A London-born British Bangladeshi student who disappeared while studying in Dhaka in 2015 and joined the Islamic State (ISIS) terrorist network in Syria has lost his UK High Court appeal against his British citizenship being withdrawn.

Ashraf Mahmud Islam, whose case will have wide repercussions on similar cases involving ISIS operatives such as Shamima Begum, was 18 years old and studying A-level law in Bangladesh when he disappeared and then resurfaced in Syria having joined ISIS.

In Jul 2017, then home secretary Amber Rudd had written to his last known address in the UK to inform his family that Islam’s British citizenship had been revoked on national security grounds in accordance with international law, as he had dual Bangladeshi nationality.

The court was urged that Ashraf Islam be allowed re-entry to the UK to face the British justice system as he is currently being held in a Kurdish-run military prison in Syria, where he could face the death penalty.

In a ruling at the Royal Courts of Justice this week, Justice Pepperall said Ashraf Islam’s detention and risk of the death penalty was “entirely because of his own actions in travelling to Syria and engaging in jihad”.

"The only action taken by the home secretary in this case has been to deprive Ashraf of his citizenship. He is not in peril in Syria because of that decision, but because he is being held on suspicion of involvement in the IS insurgency," the ruling notes.

The judge noted that he had a good life in London and that his father, Abdullah Islam, who had brought the High Court challenge on behalf of his son, had been unable to prevent him travelling to Syria to join the terror group.

The case had first been rejected by the UK’s Special Immigration Appeals Commission (SIAC) and now a judicial review in the High Court has also been denied. There is recourse to the Court of Appeal but Ashraf Islam’s contact with UK lawyers from his detention camp in Syria would prove a complex issue.

Like him, Shamima Begum, the so-called British ISIS bride of Bangladeshi origin, has also been deprived of her British citizenship as it is claimed that she has an automatic right to dual nationality by virtue of her parents – something the Bangladesh government has repeatedly denied. She also continues to be held in a Syrian detention camp, with her UK appeal yet to be listed. Her case is now likely to be affected by this week’s judgment by the UK High Court.