Pentagon bought device through undercover operation some investigators suspect is linked to Havana Syndrome

Tourists ride classic convertible cars on the Malecon beside the United States Embassy in Havana, Cuba, Oct. 3, 2017. (AP Photo/Desmond Boylan)

The U.S. Defense Department has spent more than a year testing a device purchased in an undercover operation that some investigators think could be the cause of a series of mysterious ailments impacting U.S. spies, diplomats and troops that are colloquially known 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 waning 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 offer a more specific number.

The device is still being studied and there is ongoing debate — and in some quarters of government, skepticism — over its link to the roughly dozens of anomalous health incidents that remain officially unexplained.

CNN has asked the Pentagon, HSI and the DHS for comment. The CIA declined to comment.

The device acquired 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. Although 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 kind of damage some victims have reported could be made portable; that remains a core question, according to one of the sources briefed on the device. The device could fit in a backpack, this person said.

The acquisition of the device has reignited a painful and contentious debate within the U.S. government about Havana Syndrome, known officially as “anomalous health episodes.”

The mysterious illness first emerged in late 2016, when a cluster of U.S. diplomats stationed in the Cuban capital of Havana began reporting symptoms consistent with head trauma, including vertigo and extreme headaches. In subsequent years, there have been cases reported around the world.

In the subsequent decade the intelligence community and the Defense Department have sought to understand if those officials were the victims of some kind of directed energy attack by a foreign government — with senior intelligence officials saying publicly that there wasn’t enough evidence to support that conclusion and victims arguing that the U.S. government has gaslit them and ignored important evidence that Russia was attacking American 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 acquired device and its testing.

One key concern now for some officials is that if the technology proves viable it may have proliferated, several of the sources said, meaning that more than one country could now have access to a device that may be capable of causing career-ending injuries to U.S. officials.

CNN was not able to learn where — or from whom — HSI purchased the device, but HSI has a history of collaboration with the Defense Department for operations that take place all over the globe. The office has broad jurisdiction to investigate crimes linked to customs violations, including investigations into the proliferation of U.S.-controlled technology or expertise overseas.

Those investigations are “the single biggest collaboration point between HSI and the U.S. military,” according to a former Homeland Security official.

For example, when the U.S. military came across U.S. technology in Afghanistan or Iraq that raised questions about how those components came to the region, it would turn to HSI, according to the official.

It was also not clear how the U.S. government learned of the existence of the device in order to purchase it. Havana Syndrome — and its cause — have remained frustratingly opaque to both the intelligence community and the medical community.

One problem facing the medical community is that there is still not a clear definition of “anomalous health incidents” or AHIs. Tests were done, in some cases, long after symptoms began, making it harder to understand what physically happened.

In 2022, an intelligence panel investigating the cause of AHIs 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 said publicly that it could not link any cases to a foreign adversary, ruling it unlikely that the unexplained illness was the result of a targeted campaign by an enemy of the U.S.. As recently as January of 2025, the broader intelligence community assessment remained that it was very unlikely that the symptoms were caused by a foreign actor — even as an official with the Office of the Director of National Intelligence emphasized that analysts cannot “rule out” the possibility in some small number of cases.

That stance has long incensed victims, many of whom believe strongly that intelligence exists offering black-and-white evidence that Russia is behind their symptoms, some of which have been severe enough to force retirement.

Some current and former CIA officers have raised concerns that the agency soft-pedaled its investigation, CNN has previously reported.

The acquisition of the device has been treated by some victims as potential vindication.

“If the [U.S. government] has indeed uncovered such devices, then the CIA owes all the victims a f**king major and public apology for how we have been treated as pariahs,” Marc Polymeropoulos, one of the first CIA officers to go public with injuries he says he sustained in an attack in Moscow in 2017, said in a statement to CNN.