Pentagon leak probe: Pete Hegseth’s top adviser Dan Caldwell placed on leave an ‘unauthorised disclosure’, says Report

US Defense Secretary Pete Hegseth's senior adviser Dan Caldwell was escorted from the Pentagon on Tuesday (April 15) after being identified in an investigation into leaks within the Department of Defense, as per a report.

Caldwell has been placed on administrative leave for what was described as "an unauthorised disclosure."

"The investigation remains ongoing"

Reuters citing a US official who spoke on condition of anonymity, said the official declined to provide further details on the nature of the alleged disclosure or whether it involved contact with a journalist.

"The investigation remains ongoing," the official was quoted as saying.

The development marks the latest in a series of actions taken under the Trump administration’s crackdown on unauthorised leaks, a campaign reportedly supported by Hegseth since taking the helm at the Pentagon in January.

Memo sought investigation into “unauthorised disclosures”

A memo dated March 21 and signed 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 left open the possibility of using polygraph tests in the inquiry, although it remains unclear if Caldwell underwent one, according to the news outlet.

Key adviser in Yemen strike planning

Though Caldwell has maintained a lower profile than other top officials, Reuters noted he played a crucial advisory role to Hegseth. A leaked Signal message chain published by The Atlantic last month highlighted Caldwell’s importance—Hegseth reportedly identified him as the “best staff point of contact” for the National Security Council during planning for strikes against Houthi targets in Yemen.

Not related to recent wave of firings

The action against Caldwell appears unrelated to a string of high-profile dismissals under Hegseth’s tenure. Since January, the Defense Secretary has removed several top officials, including the chairman of the Joint Chiefs of Staff, the Navy’s top admiral, the head of US Cyber Command, and the US military representative to the NATO Military Committee.