The mother of a British Islamic State (IS) member suspected of murdering hostages in Syria lost her challenge on Friday that it was illegal for the UK to assist on a US investigation which could lead to her son facing the death penalty.

Her son, El Shafee Elsheikh, is one of two UK citizens being held by Kurdish forces and suspected of belonging to an IS cell, known as “the Beatles,” which is thought to have beheaded hostages.

The US is seeking to extradite both men to the US to face prosecution which could result in the death penalty. Up until the filing of the complaint, the UK Home Secretary was cooperating with US investigators on an information-sharing basis without any assurance that the US would refrain from enforcing the death penalty.

The UK has long objected to the death penalty and typically only shares information under an assurance that the death penalty will not be an option.

The mother’s lawyers argued that the Home Secretary’s actions were inconsistent with the “UK government’s policy of unequivocal opposition to the death penalty,” and violated both the 2018 Data Protection Act, and her rights under the European Convention on Human Rights (ECHR).

The High Court reasoned that her son, in Syria, falls outside the jurisdiction of the court and therefore is not subject to the protections of the ECHR. Further, the court stated that the Secretary’s decision to provide legal assistance without an assurance does not violate common law or international law, and the underlying policy for requiring assurances permits exceptions. Therefore, London’s High Court dismissed the claim.