Two of the British ISIS terrorists dubbed the “Beatles” further incriminated themselves in the mistreatment of Western hostages in Syria, including Americans Kayla Mueller and James Foley, in interviews obtained exclusively by NBC News.

In the interviews, the two men, Alexanda Kotey and El Shafee Elsheikh, for the first time admitted their involvement in the captivity of Kayla, an aid worker who was tortured and sexually abused before her death in 2015.

Kotey said, "She was in a room by herself that no one would go in."

Elsheikh got into more detail, saying, "I took an email from her myself," meaning he got an email address the Islamic State militant group could use to demand ransom from the family. "She was in a large room, it was dark, and she was alone, and … she was very scared."

Read more: NBC News