The Central Intelligence Agency and the United States Department of Defense investigated a previously undisclosed incident in Norway in which a government researcher tested a microwave device on himself and later experienced symptoms associated with so-called Havana syndrome, according to a report published Saturday by The Washington Post.

Norwegian authorities informed the CIA about the episode, prompting at least two visits by Pentagon and White House officials to review the matter, the report said, citing individuals familiar with the situation.

Sources indicated that the test results did not establish that U.S. diplomats or intelligence personnel were targeted by a foreign adversary. However, they suggested that pulsed-energy devices may have measurable biological effects on humans.

The researcher involved was described as a prominent skeptic of claims that directed-energy weapons could produce the neurological symptoms tied to anomalous health incidents. In attempting to disprove the theory by using himself as a test subject, he reportedly developed symptoms similar to those long reported by affected U.S. personnel.

Anomalous health incidents, often referred to as AHIs, involve sudden onset symptoms including dizziness, headaches, nausea, ear pain, ringing in the ears, pressure sensations, and cognitive difficulties. Public awareness of the issue grew after a series of cases beginning in 2016 involving U.S. diplomats and intelligence officials stationed in Havana, Cuba, leading to the term “Havana syndrome.”

The U.S. government has acknowledged hundreds of reported cases among diplomats, intelligence officers, military personnel, and family members since that time.

The latest report follows earlier disclosures that Homeland Security Investigations used federal funding to test a device obtained through an undercover operation. That device, believed to emit pulsed radiofrequency energy, reportedly contains Russian components and is small enough to fit inside a backpack.

Medical findings connected to reported cases have varied. Some individuals were diagnosed with brain injuries despite imaging scans showing no visible structural abnormalities, adding to the ongoing debate within the scientific and intelligence communities about the cause of the incidents.