High Court judges have rejected a challenge against the UK's decision to share evidence about two suspected Islamic State terrorists without receiving assurances that they will not face the death penalty.

El Shafee Elsheikh and Alexanda Kotey are accused of belonging to a brutal four-man cell of IS executioners in Syria, nicknamed The Beatles because of their British accents, responsible for killing a number of high-profile Western captives.

The pair were captured in January last year, sparking a row over whether they should be returned to the UK for trial or face justice in another jurisdiction.

Elsheikh's mother, Maha Elgizouli, challenged Home Secretary Sajid Javid's decision to share 600 witness statements gathered by the Metropolitan Police with US authorities under a "mutual legal assistance" (MLA) agreement without seeking assurances that the men would not face execution if they were extradited and tried there.

But her challenge was rejected on Friday by two leading judges, who ruled that the decision was not unlawful.

The Lord Chief Justice, Lord Burnett, sitting with Mr Justice Garnham, said: "There is no general, common law duty on Her Majesty's Government to take positive steps to protect an individual's life from the actions of a third party and that includes requiring particular undertakings before complying with the MLA request."

During a hearing in October, Ms Elgizouli's lawyers said Mr Javid's decision, which was outlined in a letter to then US attorney general Jeff Sessions, was "unprecedented and unjustified" and put the suspects at risk of an "inhuman punishment".

Kotey and Elsheikh, who were raised in the UK, are believed to be detained by Kurdish forces in Syria and have been stripped of their British citizenship.

They are said to have been members of the cell which also included Mohammed Emwazi, known as Jihadi John, who was killed in a US air strike in 2015, and Aine Davis, who has been jailed in Turkey.

Emwazi appeared in a number of videos in which hostages, including British aid workers David Haines and Alan Henning and US journalists James Foley and Steven Sotloff, were killed.

The Crown Prosecution Service (CPS) decided there is "insufficient evidence" to prosecute them in the UK.

After Ms Elgizouli launched legal action, the Home Office announced in July that it had agreed to a "short-term pause" of the MLA process with the US.

Mr Javid faced intense criticism after the letter he wrote to Mr Sessions was leaked, with MPs accusing him of breaching the UK's long-standing opposition to the death penalty.

The Government's former reviewer of anti-terror legislation, Lord Carlile, branded the move "extraordinary" and said it was a "dramatic change of policy".

Prime Minister Theresa May supported Mr Javid's original decision, which was also backed by Boris Johnson when he was foreign secretary.

But the MLA sparked widespread criticism in Westminster from across the political divide.

By Sian Harrison