Christian Aid Worker Kayla Mueller, Killed During ISIS Captivity, Reportedly Married off to Extremist Militant

Feb 13, 2015 05:15 PM EST

Kayla Mueller, the Christian humanitarian worker who died while in captivity of the Islamic State terror group, was likely married off to an ISIS official during her time in captivity, a U.S. official has revealed.

On Wednesday, CNN reported that the American official, who wasn't named, used 'unspecified intelligence gleaned about the case' to determine that Mueller was paired with the ISIS fighter.The official added that while the 26 year old Arizona native was most likely gifted as a bride, it remains unclear whether she was coerced, sold or forced into the pairing

However, the National Security Council warned that "reports that have been published by certain news outlets regarding Kayla's time in (ISIS) captivity are speculative and unproven at this time."

"The U.S. government continues to analyze any information regarding Kayla's captivity but has not corroborated any of the multiple theories regarding the conditions throughout the duration of her captivity," spokeswoman Bernadette Meehan said.

According to CBS News, the extremist group sent photos to Kayla's parents, Carl and Marsha Mueller, of their daughter's body as proof of her death. One photo apparently showed the 26-year-old in a white burial shroud, which is a sign of respect in Muslim culture.

While the cause of Mueller's death remains unclear, ISIS has claimed that she was killed in a building hit during a Jordanian airstrike on Raqqa, the militants' de facto capital in Syria. However, experts have dismissed the claim as baseless, as ISIS offered no other proof than an image of a building in rubble.

Mueller, who is the fourth American killed while held captive by the militant group, had traveled to Syria to help children affected by the nation's bloody civil war. However, in August 2013, she was kidnapped by the Islamic State while working at a Doctors Without Borders hospital in Aleppo.

During her captivity, Mueller sent her family an emotional letter, which they received in the Spring of 2014. In the letter, the aid worker revealed how she drew comfort from her strong faith in God.

She wrote, "I remember mom always telling me that all in all in the end the only one you really have is God. I have come to a place in experience where, in every sense of the word, I have surrendered myself to our creator b/c literally there was no else....+ by God + by your prayers I have felt tenderly cradled in freefall."

On Tuesday, U.S. President Barack Obama released a statement insisting that no matter what it takes, the United States "will find and bring to justice the terrorists who are responsible for Kayla's captivity and death."

He added, "Kayla's compassion and dedication to assisting those in need shows us that even amongst unconscionable evil, the essential decency of humanity can live on."