The last American hostage known to be held by the Takfiri group ISIL, was confirmed dead by her relatives and the White House on Tuesday.

The last American hostage known to be held by the Takfiri group ISIL, was confirmed dead by her relatives and the White House on Tuesday.

Kayla Jean Mueller’s parents received what US officials described as private communications from Islamic State over the weekend, including photographs.

Based on the images, US intelligence agencies concluded they proved she had been killed, officials said, according to Wall Street Journal.

However, intelligence officials couldn’t determine how she was killed or when she died, White House press secretary Josh Earnest said.

ISIL asserted Friday that Mueller had been killed in a Jordanian airstrike in Syria. But US and Jordanian officials have been skeptical of the claim.

US officials said it was impossible to ascertain from the photos whether she had been killed in the recent strikes as the group claimed.

The US military isn’t conducting an investigation to determine whether Mueller was killed by the Jordanian airstrikes because defense officials don’t consider the Islamic State claims to be credible, said Rear Adm. John Kirby, the Pentagon press secretary.

One US official said militants sent Mueller’s family three photos showing her face. In two of them, she was wearing a head scarf and, in the third, she appeared to be in a burial shroud. It was clear that she had recently died, but it wasn’t possible to know when the photos were taken.

Her parents, Marsha and Carl Mueller, had held out hope their daughter was alive even after ISIL announced her death on Friday. But in a statement on Tuesday, they said they had received confirmation of her death.