Hegseth adviser placed on leave after investigation into Pentagon leaks | US military

One of US defense secretary Pete Hegseth’s leading advisers, Dan Caldwell, was reportedly put on leave and removed from the Pentagon on Tuesday following a Department of Defense investigation into leaks.

Caldwell was escorted out of the Pentagon after being identified during the investigation and subsequently placed on administrative leave for “an unauthorized disclosure”, a source told Reuters.

“The investigation remains ongoing,” the source, an official within the administration, said. The source did not go into detail about the alleged disclosure of information, and they did not reveal whether it was made to a journalist or another entity.

A memo signed 21 March by Hegseth’s chief of staff, Joe Kasper, requested an investigation into “recent unauthorized disclosures of national security information involving sensitive communications”. The memo also mentions a potential “use of polygraphs in the execution of this investigation” but it is not currently known if Caldwell was subjected to a polygraph test.

“I expect to be informed immediately if this effort results in information identifying a party responsible for an unauthorized disclosure, and that such information will be referred to the appropriate criminal law enforcement entity for criminal prosecution,” Kasper wrote in the letter.

Caldwell has played a significant role as Hegseth’s adviser, with the defense secretary naming Caldwell as the best staff point of contact for the National Security Council as it prepared for the launch of strikes against the Houthis in Yemen in the leaked Signal chat published by the Atlantic last month.

The decision to put Caldwell on administrative leave is reportedly separate from the wave of federal firings in the past few weeks under the Trump administration.

Caldwell, a Marine Corps veteran, previously worked for Concerned Veterans for America, a non-profit group with strong ties to Republican lawmakers and promoting conservative policies.

He had worked with Hegseth at that organization before he joined Hegseth’s defense department team.