Washington DC - An insider alleged that Homeland Security Secretary Kristi Noem and her de facto chief of staff, Corey Lewandowski, fired a Coast Guard pilot over a bag that contained something embarrassing.

Current and former Coast Guard officials told NBC News that last May, Lewandowski verbally berated Coast Guard flight staff and threatened to fire them for taking off without Noem's heated blanket.

At the time of the incident, the plane had only reached 10,000 feet, and the seatbelt sign was yet to be switched off.

"There is a general atmosphere of 'keep your head down; you don't want to be on the firing line,'" the officials said, revealing a fear among DHS staff of angering Noem.

In response to the blanket incident, the Coast Guard pilot was initially relieved of his duty and asked to take a commercial flight home. But when there was no one else to pilot Noem's plane, he was rehired.

Recent reports from the Daily Mail, however, cite three DHS sources that deny the incident was really triggered by Noem's heated blanket.

"This was never about a blanket," one insider told the Daily Mail. "The blanket was a cover story for what really happened. The whole thing was really about the bag that was left."

According to reports, Noem had left a personal bag on another plane after swapping aircrafts for the return flight to Washington, DC.

The contents of the bag are still unknown, but sources told the Daily Mail that Lewandowski got angry because he and Noem were fearful that the discovery of its contents could be embarrassing.

A FEMA official was cited by New York Magazine last year as implying that Noem and Lewandowski are in the midst of an affair and their relationship is the "worst-kept secret in DC."