A Pentagon watchdog has determined that Defense Secretary Pete Hegseth risked the safety of U.S. servicemembers by sharing sensitive military information on the Signal messaging app, according to a source who has reviewed the forthcoming inspector general report. 

The report, which is expected to be released as early as Thursday, was launched after a journalist for The Atlantic revealed in March that he had been added to a chat on the encrypted messaging app in which Hegseth and other top officials were discussing plans for U.S. airstrikes against Houthi rebels in Yemen. 

A summary of the report provided to NPR finds that had a foreign adversary intercepted the intelligence discussed in the chat, it would have endangered both U.S. servicemembers and the mission at large. 

The investigation was conducted by Pentagon Inspector General Steven Stebbins. His findings were shared with NPR by a source who has seen the document but was not authorized to discuss it publicly.

The report concludes that Hegseth, who sent the information about targets, timing and aircraft to two Signal groups, including his wife and brother, violated Pentagon policies about using personal phones for official business. Hegseth would not sit for an interview with investigators, the report said, and would only provide a written response.

In his response, Hegseth stated that he was able to declassify information; the inspector general did not determine whether Hegseth had declassified information in the chat by the time it was shared, but acknowledged that, as secretary of defense, he had the authority to do so.

Hegseth also told the inspector general that he believed the investigation was political and that he lacked faith in Stebbins, according to the source.

In a statement, chief Pentagon spokesman Sean Parnell said the findings absolved Hegseth of any wrongdoing.

“The Inspector General review is a TOTAL exoneration of Secretary Hegseth and proves what we knew all along — no classified information was shared. This matter is resolved, and the case is closed,” Parnell said.

In a separate statement, White House press secretary Karoline Leavitt defended President Trump’s national security team and its handling of sensitive information.

“This review affirms what the Administration has said from the beginning — no classified information was leaked, and operational security was not compromised,” Leavitt said. 

The report is the product of months of investigation. The probe was launched in April in response to a request from the top Republican on the Senate Armed Services Committee, Roger Wicker of Mississippi, and Jack Reed, the panel’s top Democrat. 

Over the course of the investigation, the report states, Hegseth only provided a few of his Signal messages to the inspector general. As a result, Stebbins was forced to rely mostly on screenshots of the chat from the Atlantic, according to the source. 

One member of the Armed Services committee, Arizona Democrat Mark Kelly, responded to the report by saying “it’s pretty clear he shouldn’t have been using his cell phone and an unsecure app, unofficial app with regards to DOD, to be sharing that kind of information.” 

“It’s not too hard to see how our adversaries can get that information and pass it on, to the Houthies in this case, and put those lives at risk,” Kelly said. 

The report’s expected release comes as Hegseth faces pressure to answer for the administration’s controversial campaign to strike boats in the Caribbean Sea that are allegedly carrying drugs to the U.S. from South America. One of those strikes has forced the administration to answer questions about whether the U.S. fired on the survivors of a bombing on Sept. 2, a move that military experts say could constitute a war crime if the administration’s claim to be at war with narco traffickers is to be accepted. 

Hegseth’s leadership at the Pentagon has been dogged by controversy. Critics have highlighted that the Army National Guard combat veteran and former Fox News host lacks the same level of experience as his predecessors at DOD. 

In his Senate confirmation hearing, the social conservative told lawmakers that “lethality, meritocracy, warfighting, accountability and readiness” were his top priorities for the role. Since being sworn in, he’s overseen the agency through drastic changes, firing several top officials, placing restrictions on troops and veterans that are transgender and rebranding the agency as the Department of War. 

The White House reiterated continued confidence in Hegseth on Wednesday, with Leavitt saying in a statement that, “President Trump stands by Secretary Hegseth.”

NPR disclosure: Katherine Maher, the CEO of NPR, chairs the board of the Signal Foundation.

Gabriel Sanchez contributed reporting.