An ongoing, five-year 60 Minutes investigation into Havana Syndrome sparked new concerns in Washington. 

The March 31 report broadcast on 60 Minutes revealed new evidence of a potential Russian nexus tied to mysterious illnesses suffered by U.S. national security officials. In response, a bipartisan group of lawmakers last week sent a letter to President Biden calling for a “renewed assessment by the U.S. government” of what officials call “anomalous health incidents.” 

“At this time, we recognize that we must not let allegations carry more weight than evidence,” the members of Congress wrote. “However, the 60 Minutes piece presented compelling evidence that warrants further review.”

The letter was signed by, among others, Sen. Susan Collins (R-ME), a senior member of the U.S. Senate Intelligence Committee, and Sen. Jeanne Shaheen (D-NH), a senior member of the U.S. Foreign Relations and Armed Services Committees. 

“There is no higher priority than the health and safety of American government employees and family members who commit their lives to advance U.S. national security interests,” they wrote. “We must do everything we can to protect them.”

White House Press Secretary Karine Jean-Pierre, Deputy Pentagon Press Secretary Sabrina Singh and State Department spokesperson Matthew Miller all addressed the 60 Minutes report after it aired. 

“We will look at new information as it comes in and make assessments inside the State Department and with our Intelligence Community counterparts,” Miller said the day after the 60 Minutes report.

An official U.S. intelligence assessment released last year found that it was “very unlikely” a foreign adversary was responsible for Havana Syndrome. The assessment did acknowledge that some intelligence agencies have only “low” or “moderate” confidence in that conclusion.

Greg Edgreen, a now-retired Army lieutenant colonel who ran the Pentagon investigation into anomalous health incidents, told 60 Minutes that the bar for proof was set impossibly high. Edgreen said he focused on Moscow early on in his investigation.

White House staff, CIA officers, FBI agents, and military officers and their families are among those who believe they were wounded by a secret weapon firing a high-energy beam of microwaves or ultrasound. 

“And consistently there was a Russia nexus,” Edgreen said. “There was some angle where they had worked against Russia, focused on Russia, and done extremely well.”

The 60 Minutes investigation, conducted jointly with The Insider and Der Spiegel, tied one victim, an FBI agent, to work involving Russia. Evidence suggests that Vitalii Kovalev, a Russian man she interviewed extensively, was a spy. Mark Zaid, the agent’s attorney, has more than two dozen clients suffering symptoms of Havana Syndrome. He said victims include members of the CIA, State Department and FBI.

“The one thread that I know of with the FBI personnel that is common among most, if not all, of my clients other than the family members connected to the employee, was they were all doing something relating to Russia,” Zaid, who holds a security clearance, said.

A spokesman for the Kremlin responded to the 60 Minutes report by saying allegations against Russia are unfounded.