A former U.S. Air Force intelligence officer who had been preparing to speak with Congress about alleged secret government programs involving unidentified aerial phenomena was found to have died from an accidental drug overdose, according to a state medical examiner’s report, contradicting prior public claims that the death was suspicious.

Matthew James Sullivan, 39, of Falls Church, Virginia, died on May 12, 2024, from a combination of alcohol and multiple prescription medications, including alprazolam, cyclobenzaprine, and imipramine. The Northern Virginia medical examiner’s office ruled the manner of death as accidental, not suicide.

The findings stand in contrast to statements made by Eric Burlison, who said in an April interview that Sullivan had “suspiciously committed suicide” shortly before he was expected to provide information to congressional investigators regarding UFO-related matters.

In a letter sent April 16 to FBI Director Kash Patel, Burlison called for a federal investigation, citing what he described as potential national security implications. The letter referenced Sullivan’s planned testimony and raised concerns about possible foul play surrounding the circumstances of his death.

The FBI has acknowledged broader efforts to examine connections among a number of missing or deceased scientists and officials linked to classified aerospace and defense programs but has not confirmed whether Sullivan’s case is part of a specific investigation.

Sullivan was a decorated veteran who received a Bronze Star for valor during Operation Enduring Freedom and served in multiple intelligence roles, including assignments with the Air Force Intelligence Agency, the National Air and Space Intelligence Center, and the National Security Agency.

Lawmakers, including James Comer, who chairs the House Oversight Committee, have requested briefings from federal agencies as part of a broader inquiry into more than a dozen reported deaths and disappearances involving individuals connected to sensitive government programs.

Burlison has also cited involvement from David Grusch, who previously testified before Congress about alleged government knowledge of unidentified aerial phenomena and had reportedly been assisting Sullivan ahead of his planned disclosures.

The Intelligence Community Inspector General has declined to comment on whether any related investigations are ongoing. The case remains part of a wider congressional focus on transparency surrounding classified aerospace research and reported unexplained incidents.