Two British Islamic State fighters – part of a group nicknamed 'the Beatles' – have been captured in Syria, US officials say.
Alexanda Kotey and El Shafee ElSheikh were detained by Kurdish forces in Syria and have reportedly revealed "valuable information" on the IS leadership and structure.
The Londoners were the last members of the bloodthirsty group of four Britons still at large.
Along with 'Jihadi John' Mohammed Emwazi and Aine Davis, they are believed to have tortured and beheaded dozens of people.
British aid workers Alan Henning and David Haines, and American journalists James Foley and Steven Sotloff were among their suspected victims – beheaded in brutal videos released on the internet.
The group was nicknamed the Beatles because of their English accents.
Ringleader Emwazi was killed in a drone strike in 2015 and Davis is in jail in Turkey after being convicted last year on terrorism charges.
The US government believes the group beheaded more than 27 hostages and used torture methods such as waterboarding and electrocution.
Kotey and ElSheikh were captured in early January by the US-backed Syrian Democratic Forces, said an American defence official.
A statement confirmed they were suspected of the "detention, exploitation and execution of Western detainees… and are thought to have links to the British terrorist often called Jihadi John".
The pair were handed over to US special forces, according to the New York Times, with their identities confirmed using fingerprints and other measurements.
Under interrogation they gave up "valuable information" on Islamic State's remaining leadership and structure, the newspaper reported.
ElSheikh is a former child refugee from Sudan who lived in White City, west London, and once worked as a mechanic.
He is "said to have earned a reputation for waterboarding, mock executions, and crucifixions while serving as an ISIS jailer", the US State Department said in March 2017.
Kotey, from Paddington, was born in London and is believed to have helped recruit other Britons to fight for IS, which has now been driven out of its Syria strongholds.
He "likely engaged in the group's executions and exceptionally cruel torture methods, including electronic shock and waterboarding", according to the State Department.
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Emwazi, who appeared in black in the infamous beheading videos, was born in Kuwait and moved to the UK with his family when was six.
He went to state schools, then studied computer science at the University of Westminster before leaving for Syria in 2013.