Two British ISIS members of a group dubbed "The Beatles" have allegedly admitted involvement in the mistreatment of US citizen Kayla Mueller.
In interviews obtained by NBC Alexanda Koteyand El Shafee Elsheikh appear to admit their involvement in the captivity of the aid worker.
Ms Mueller was tortured and sexually abused before her death in 2015.
In the interviews, Kotey reportedly said that Ms Mueller was kept in a room by herself.
"She was in a room by herself that no one would go in", he said.
Elsheikh also reportedly said he took an email from the aid worker to demand ransom from her family.
"I took an email from her myself", he said.
"She was in a large room, it was dark, and she was alone, and … she was very scared."
ISIS demanded that Ms Mueller's family send them €5 million or they would send them a picture of their daughter's dead body.
Elsheikh is also said to admit to hitting American journalist James Foley while he was in captivity.
Mr Foley was later beheaded by Jihadi John in 2014.
According to NBC Elsheikh said that Mr Foley would often risk taking abuse from guards to make sure other prisoners had eaten enough food.
“If the guard would ask, ‘Is the food enough?" some of the other prisoners were very timid", he said.
"It was always him who would say, ‘It's not enough’” and take the risk of retaliation from guards."
