A British terrorist accused of beheading Western hostages for the so-called Islamic State has pleaded guilty to multiple charges in a US federal court.

Alexanda Amon Kotey, 37, was one of the gang of four IS militants nicknamed “the Beatles” by their captives due to their British accents.

The cell – said to be made up of ringleader Mohammed Emwazi, known as Jihadi John, Aine Davis, El Shafee Elsheikh and Kotey – was allegedly responsible for the brutal killings of a number of Western and Japanese captives, including Britons Alan Henning and David Haines.

The slayings sparked outrage and revulsion around the world after being broadcast in graphic detail.

Kotey, who grew up in London, attended a change of plea hearing at US District Court in Alexandria, Virginia, and pleaded guilty to eight charges.

They were four counts of hostage taking resulting in death, conspiracy to commit hostage taking resulting in death, conspiracy to murder United States citizens outside of the United States, conspiracy to provide material support to terrorists – hostage taking and murder – resulting in death and conspiracy to provide material support to a designated foreign terrorist organisation resulting in death.

District Judge TS Ellis read out the charges against Kotey and told him he faced life in prison after the US government agreed not to seek the death penalty.

Kotey said he understood.

Family members of the American victims – journalist James Foley, journalist Steven Sotloff and aid workers Peter Kassig and Kayla Mueller – were also in the court to hear details of the charges.

Prosecutors said they did not wish to speak at the hearing.

Details of Kotey’s plea agreement were read out in court, revealing the Briton has agreed to fully co-operate with the US government.

He will provide “full, complete and truthful” evidence to not only the US but all foreign governments.

Kotey will provide all relevant documents, meet with victims’ families if they wish to do so and voluntarily submit to a lie detector test.

However, the terrorist will not be compelled to give evidence in court against co-defendant Elsheikh, the hearing was told.