The Biden administration has acquired a pulsed energy weapon that experts believe could be linked to “Havana Syndrome,” a mysterious condition that has affected U.S. diplomats and government workers abroad since late 2016, Fox News has learned.

The weapon, which reportedly contains Russian components but is not entirely Russian in origin, was purchased toward the end of the Biden administration and has undergone more than a year of Pentagon testing. The device is believed to be capable of producing pulsed radio waves similar to those suspected of causing the ailments collectively known as Anomalous Health Incidents (AHI).

House Republicans are now demanding answers about the procurement. House Committee on Homeland Security Chairman Andrew Garbarino (R-N.Y.) has sent a letter to Homeland Security requesting detailed information about the weapon’s purchase process, costs, and findings from its year-long testing related to Havana Syndrome.

“The device in question is described as capable of producing pulsed radio waves and containing Russian components, though it is supposedly not entirely Russian in origin,” Garbarino stated in his letter. After being acquired by Homeland Security Investigations (HSI), the device was reportedly transferred to the Department of Defense for extensive testing of its capabilities.

The mysterious ailments first came to light in late 2016 when American personnel stationed at the U.S. Embassy in Havana reported unusual symptoms including pressure sensations in the brain, vertigo, tinnitus, and cognitive impairment. The individual identified as “Patient Zero,” whose identity Fox News agreed to protect under the pseudonym Adam, experienced multiple attacks while on assignment in Cuba.

The Havana Syndrome phenomenon has since been reported by U.S. personnel in multiple countries, sparking international concern about potential targeted attacks against American officials. Symptoms typically include unexplained head pressure, dizziness, nausea, and in some cases, long-term neurological effects.

Intelligence agencies remain divided on whether foreign adversaries are behind these incidents. An assessment from the Office of the Director of National Intelligence (ODNI) presented a majority view concluding that it was “very unlikely” that a foreign actor “used a novel weapon or prototype device to harm even a subset of the U.S. Government personnel,” with five out of seven agencies supporting this conclusion.

However, Garbarino noted in his letter that “two agencies dissented from the majority view and assessed that there was a chance that foreign actors may have developed some sort of ‘novel weapon or prototype device’ that could have harmed U.S. personnel.”

The debate over the cause of Havana Syndrome has evolved in recent months. The ODNI released a report indicating that new intelligence “led two components to shift their assessments about whether a foreign actor has a capability that could cause biological effects consistent with some of the symptoms reported as possible AHIs.”

This shift in assessment suggests a growing concern within some intelligence circles that directed-energy weapons might indeed be responsible for at least some of the reported incidents. The ODNI stated that “this shift consequently led two IC components to subtly change their overall judgment about whether a foreign actor might have played a role in a small number of events.”

The acquisition of this weapon by U.S. authorities represents a significant development in understanding the potential causes of Havana Syndrome. Testing such a device could help researchers better comprehend the physical mechanisms that might produce the reported symptoms and potentially develop countermeasures to protect U.S. personnel abroad.

The purchase also highlights ongoing security concerns about directed-energy weapons and their potential use against American interests. As technologies advance, the ability to detect and defend against such threats becomes increasingly important for national security.

The House Committee on Homeland Security’s inquiry reflects continued congressional interest in resolving questions surrounding Havana Syndrome cases, ensuring proper care for affected personnel, and identifying appropriate security measures for U.S. government workers serving abroad.