WASHINGTON — The Defense Department’s independent watchdog is declining to investigate a U.S. Army helicopter flight near the home of musician Kid Rock and at a “No Kings” protest against President Donald Trump, according to a letter from the Pentagon’s new inspector general.

The letter, dated April 24 and released on Thursday by a nonprofit advocacy group, said Defense Secretary Pete Hegseth had the authority to terminate any administrative review. It said the Pentagon chief had “decided not to pursue this matter” and that the inspector general “will not investigate” his decision.

The letter was addressed to Donald Sherman, the president of Citizens for Responsibility and Ethics in Washington, who posted it online after requesting the inspector general look into the unusual use of U.S. military equipment.

“This response is antithetical to the role of an inspector general, and is something we’ve never seen before,” Sherman said in a statement. “Inspectors General need to be independent, not defer to the head of their agency. This incident raises serious questions about the potential misuse of military aircraft, abuse of taxpayer funds and public safety.”

Hegseth has publicly supported the pilots and Kid Rock over the episode. The pilots were initially suspended by the Army for their flight near the musician’s home but Hegseth later reversed that decision.

Trump’s defense chief later said he joined Kid Rock aboard a U.S. Army Apache helicopter and posted photos of the musician visiting the Pentagon.

Citizens for Responsibility and Ethics in Washington alleged the flight over the pro-Trump entertainer’s home in late March, and above a “No Kings” demonstration appeared to be “a staged political stunt” using U.S. military equipment at taxpayer expense.

The group argued the Defense Department’s inspector general, Platte Moring, should probe the matter to see if it violated federal or departmental ethics rules, and asked how much taxpayer funds were spent on the flybys.