Defense Secretary Pete Hegseth (C) arrives for a news conference at the Pentagon on June 22, 2025 in Arlington, Virginia. (Andrew Harnik/Getty Images)
The investigation to identify leakers within the Department of Defense began in late March with a memo from Joe Kasper, then Hegseth’s chief of staff.
"Recent unauthorized disclosures of national security information involving sensitive communications with principals within the Office of the Secretary of Defense demand immediate and thorough investigation," Kasper wrote in the March 21 memo.
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"The use of polygraphs in the execution of this investigation will be in accordance with applicable law and policy," Kasper added.
The White House and the Pentagon did not immediately respond to Fox News' request for comment.
The Pentagon in Washington, DC, on May 10, 2023, in an aerial view. (DANIEL SLIM/AFP via Getty Images)
The revelation is the latest controversy at the Pentagon, which earlier this year endured the 'Signalgate' scandal. Discussions about military action between Hegseth and a group of top Trump officials were leaked, despite being conducted on the encrypted app.
Then-national security advisor Michael Waltz assumed "full responsibility" for the misstep of including the Atlantic's editor-in-chief Jeffrey Goldberg on the Signal chat alongside Vice President JD Vance, Secretary of State Marco Rubio, CIA Director John Ratcliffe and Hegseth.
NATIONAL SECURITY ADVISOR MIKE WALTZ TAKES RESPONSIBILITY FOR 'EMBARRASSING' SIGNAL CHAT LEAK
In the aftermath of the accidental leak to a journalist about impending U.S. military strikes on Houthi targets in Yemen, Trump has remained firmly in Hegseth’s corner, offering public support.
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Amanda covers the intersection of business and geopolitics for Fox News Digital.
https://www.foxnews.com/politics/white-house-orders-hegseth-stop-polygraph-tests-pentagon-staff