The parents of Kayla Mueller, who had been held hostage by ISIS since August 2013, confirmed earlier today that they have been notified of their daughter's death.

ISIS has claimed that Mueller was killed by a Jordanian airstrike, although that has not been confirmed.

Catherine Herridge reported some riveting new details today on "The Real Story," information that she had been previously asked by intelligence officials not to disclose for national security reasons.

Herridge said she could now share some of the information she received from her contact, such as new details on Mueller's kidnapping, the locations where Western hostages were held in Syria and the White House's delay in approving a rescue attempt last year.

"She was traveling with a Syrian man who she introduced as her boyfriend to her colleagues," Herridge said of Mueller's abduction. "They were not far from Aleppo when their car was forced off the road and the two were kidnapped together."

According to Herridge, some days later, the Syrian man was released by ISIS and there was a question at the time if he was bait in order to kidnap Mueller.

That was later dismissed after the man went back to ISIS in an unsuccessful attempt to secure Mueller's release.

Herridge also reported the locations where the hostages were held in Syria - largely together in the same places - between November 2013 and May 2014.

"One was Aleppo, another was an industrial area known as Shaykh Najjar and the third was in the ISIS stronghold of Raqqa," Herridge said.

"By the spring of 2014, the ISIS captors, we're told, felt so confident in their situation that there was very little visible security around the hostages. And by May, eight Western hostages were held together in one location," Herridge said.

She added that Mueller was kept separate from the men, but she was able to communicate with other Western hostages, including James Foley, that she was not being mistreated or abused by her ISIS captors.

According to Herridge, there was very specific intelligence about the location of a group of Western hostages in May 2014, so specific that intelligence officials even knew in which building they were being held.

"The question is why there was such a delay by the White House to act on this information," Herridge said. "They did not OK the rescue operation until about seven weeks later. And there was clearly a fundamental disconnect between the quality of the intelligence, which the rescue team felt was of a sufficient level that they could act, and what was described to me as a significant delay on behalf of the White House, asking for the intelligence to build up further before they would act."

Herridge said that this was the last and best opportunity to rescue all of the hostages together, because after ISIS learned of the possible raid, the hostages were no longer held together.

As for comments from White House Press Secretary Josh Earnest that there is at least one other American hostage being held in Syria, Herridge said that she finds Earnest's comments confusing.

She said the only hostage who is publicly known is Austin Tice, who is reportedly not being held by ISIS, but by another group.

"Really, what the White House said on the record today is that, in fact, there is probably more than one other hostage that remains in the custody of a foreign, likely terrorist, group."

Watch the full report above and stay tuned to Fox News for more of Catherine Herridge's reports on the situation.