image sourceEPAimage captionAlexanda Kotey faces charges of conspiring to murder four US hostages
An Islamic State (IS) group suspect from the UK has pleaded guilty in a US court to charges of conspiring to murder four American hostages.
Alexanda Kotey is accused of belonging to an IS cell dubbed "The Beatles" involved in kidnappings in Iraq and Syria.
Kotey and fellow "Beatle" El Shafee Elsheikh initially pleaded not guilty at a hearing last October.
The change of plea suggests Kotey may co-operate with prosecutors.
Kotey, 36, and Elsheikh, 32, are on trial for their involvement in the murders of US journalists James Foley and Steven Sotloff, and relief workers Peter Kassig and Kayla Mueller.
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They were flown from US custody in Iraq last year to face the charges, which carry a maximum penalty of life in prison.
There is no word yet on whether Mr Elsheikh has reached a plea deal with authorities.
Both men are suspected of involvement in the deaths of other hostages, including Alan Henning – a British taxi driver who was delivering aid – and Scottish aid worker David Haines, as well as two Japanese nationals.
The duo also face separate charges of supporting terrorism and conspiring to commit hostage-taking.
Originally from west London, their alleged IS gang was given its 1960s pop group nickname by hostages due to their British accents. They were stripped of their UK nationality in 2018.
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Some of the victims were beheaded, with their deaths filmed and broadcast on social media.
The group's alleged ringleader, Mohammed Emwazi, known as "Jihadi John", died in a drone strike in 2015.
Another gang member, Aine Davis, was arrested and imprisoned in Turkey.
Kotey and Elsheikh remained at large until they were captured in 2018 by Syrian Kurds fighting IS.
The US government had wanted to put them on trial but was lacking evidence.
The men were in a legal limbo for several months, held by the US military in Iraq where the US attorney general threatened to hand them over to local courts, known for their summary justice and executions.
But the US said it would not carry out the death penalty if the men were convicted in a US court.
British counter-terrorism officials have since shared crucial evidence on the men with US officials.
media captionInterview with Islamic State 'Beatles' duo