Before her death earlier this year, American hostage Kayla Mueller was repeatedly raped by the top leader of ISIS, Abu Bakr al-Baghdadi, according to counter-terrorism officials.

Mueller’s family confirmed to ABC News that government officials have told them that their daughter, who would have turned 27 on Friday, was the victim of repeated sexual assaults by al-Baghdadi.

“We were told Kayla was tortured, that she was the property of al-Baghdadi. We were told that in June by the government,” Kayla’s parents, Carl and Marsha Mueller, told ABC News.