The Defense Department has spent more than a year testing a device acquired in an undercover operation that some investigators believe could be the cause of a series of mysterious ailments affecting American spies, diplomats and troops known colloquially as Havana Syndrome, according to four sources briefed on the matter.
A division of the Department of Homeland Security, Homeland Security Investigations, purchased the device for millions of dollars in the final days of the Biden administration, using funding provided by the Defense Department, according to two of the sources. Officials paid “eight figures” for the device, these people said, declining to provide a more precise number.
The device is still being studied, and there is ongoing debate — and in some quarters of the government, skepticism — about its connection to about a dozen anomalous health incidents that remain officially unexplained.
CNN has requested comment from the Pentagon, HSI and DHS. The CIA declined to comment.
The device purchased by HSI produces pulsed radio waves, one of the sources said, which some officials and academics have speculated for years could be the cause of the incidents. While the device is not entirely Russian in origin, it contains Russian components, this person added.
Officials have long struggled to understand how a device powerful enough to cause the damage some victims have reported could be portable; that remains a basic question, according to one of the sources with knowledge of the device. The device could fit in a backpack, this person said.
The acquisition of the device reignited a painful and controversial debate within the US government about Havana Syndrome, known officially as “abnormal health episodes”.
The mysterious illness first emerged in late 2016 when a group of US diplomats stationed in the Cuban capital Havana began reporting symptoms consistent with head trauma, including vertigo and extreme headaches. In the following years, cases were reported around the world.
Over the next decade, the intelligence community and the Department of Defense sought to understand whether those officials were the victims of some kind of directed energy attack by a foreign government — with senior intelligence officials saying publicly that there was insufficient evidence to support that conclusion, and the victims claiming that the U.S. government stopped them and ignored important evidence that Russia was targeting U.S. government officials.
Still, defense officials considered their findings serious enough that they briefed the House and Senate intelligence committees late last year, including reference to the purchased device and its testing.
A key concern now for some officials is that if the technology proves viable, it could have proliferated, multiple sources said, meaning more countries could now have access to a device that could be capable of causing career-ending injuries to U.S. officials.
CNN was unable to learn where — or from whom — HSI acquired the device, but HSI has a history of working with the Department of Defense on operations that take place around the globe. The office has broad jurisdiction to investigate crimes related to customs violations, including investigations into the proliferation of US-controlled technology or expertise abroad.
These investigations are “the largest point of collaboration between HSI and the US military,” according to a former Homeland Security official.
For example, when the U.S. military encountered U.S. technology in Afghanistan or Iraq that raised questions about how those components got into the region, it would turn to HSI, according to the official.
It was also unclear how the US government learned of the device’s existence in order to purchase it. Havana Syndrome – and its cause – have remained frustratingly opaque to both the intelligence and medical communities.
A problem facing the medical community is that there is still no clear definition of “abnormal health incidents” or AHI. The tests were done, in some cases, long after the symptoms started, making it harder to understand what happened physically.
In 2022, an intelligence panel investigating the cause of AHI said that some of the episodes could “plausibly” have been caused by “pulsed electromagnetic energy” emitted by an external source.
But in 2023, the intelligence community publicly said it could not link any cases to a foreign adversary, deeming it unlikely that the unexplained illness was the result of a targeted campaign by a US enemy. As of January 2025, the broader assessment of the intelligence community remained that the symptoms were highly unlikely to be caused by a foreign actor – even though an official in the Office of the Director of National Intelligence emphasized that analysts could not “rule out” the possibility in a small number of cases.
That position has long angered victims, many of whom strongly believe there is information providing black-and-white evidence that Russia was behind their symptoms, some of which were severe enough to force retirement.
Some current and former CIA officers have expressed concern that the agency has slowed its investigation, CNN previously reported.
The purchase of the device was treated by some victims as potential justification.
“If [US government] indeed discovered such devices, then the CIA owes all victims a major and public apology for the way we were treated like pariahs,” Marc Polymeropoulos, one of the first CIA officers to go public about the injuries he says he suffered in an attack in Moscow in 2017, said in a statement to CNN.
CNN’s Kylie Atwood contributed to this story.
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