Two British jihadists who were part of the notorious Islamic State "Beatles" quartet have for the first time admitted their involvement in the mistreatment of western hostages, including the American aid worker Kayla Mueller.
Alexanda Kotey and El Shafee Elsheikh now say they were "liaisons" to western hostages who were tortured and killed in Syria, among them Mueller, who the US State Department believes was repeatedly raped by then Islamic State leader Abu Bakr al-Baghdadi.
"I took an email from her myself," Elsheikh, 32, said in an interview obtained by NBC published on Thursday. "She was alone, I saw she was very scared."
"She was in a room by herself that no one would go in," the 36-year-old Kotey said.
The two men previously denied ever meeting Mueller, who the Islamic State held for 18 months before her death in 2015.
"Who? Remind me," Elsheikh said when asked by the BBC in 2018 if he had met the aid worker.
"Didn't meet any foreign non-Muslims," Kotey added.
The pair, who were captured in Syria by Kurdish fighters in 2018, also now admit to having beaten western hostages, who dubbed their captors "The Beatles" because of their British accents.
"I never denied that they was ever hit," Kotey said.
After previously declining to talk about their role in the "Beatles", the men said they acted as "liaisons" between the hostages and their families, demanding millions of dollars in ransom payments.
The pair are currently in legal limbo, held in Iraq by US forces, who are seeking to prosecute them in an American court.
The two have been stripped of their British citizenship but in March the Supreme Court ruled that evidence gathered by British investigators should only be admitted to a US trial if the death penalty is not sought.
US and British authorities agree that the "Beatles" were responsible for 27 killings, including the beheadings of British aid workers David Haines and Alan Henning, and Americans James Foley, Steven Sotloff and Peter Kassig.
The gang's ringleader Mohammed Emwazi, dubbed Jihadhi John, was killed in an air strike in Syria in 2015. A fourth member, British Muslim convert Aine Davis, was sentenced to prison in Turkey on terrorism charges.
The families of the murdered American hostages believe prosecuting Kotey and Elsheikh in the US is their best chance for justice.
"Like any grieving relatives, we want to know the full truth about what happened to our loved ones, and we want to see our children's murderers held accountable," they wrote in the Washington Post on Thursday. "These things can happen only if the suspects are put on trial before a jury in an American court of law."
Mueller's parents fear the two men will receive a lenient sentence if the UK prosecutes them.
"I don't think anything should be taken off the table," Marsha Mueller told NBC, referring to capital punishment.
According to the US State Department, Kotey likely "engaged in the group's executions and exceptionally cruel torture methods, including electronic shock and waterboarding".
He also acted as an Islamic State recruiter, responsible for several other UK nationals joining the terrorist group, it said.
ElSheikh travelled to Syria in 2012 and joined Al Qaeda before switching allegiance to the Islamic State. The State Department said he "earned a reputation for waterboarding, mock executions and crucifixions while serving as an ISIS jailer".
The pair still deny these allegations but Mueller's parents believe the men did worse than what they now admit to.
Investigators working with the Mueller family also believe the pair know more than they have let on and could provide details about the whereabouts of Mueller's body, which like the other victims of "the Beatles" has not been discovered.
"They're admitting that they were there," her father Carl Mueller told NBC. "Of course they're not going to tell the dark side of the story."