Sen. Rand Paul, R-Ky., said Tuesday that he has subpoenaed Dr. Anthony Fauci, the former top U.S. infectious disease official, after Fauci backed out of an agreement to testify voluntarily before the Senate Homeland Security and Governmental Affairs Committee.

The subpoena is the first issued by Paul as chairman of the committee, The Hill reported.

“Last week, Anthony Fauci notified us that he will not voluntarily testify before the Senate Homeland Security and Governmental Affairs Committee, even though he had previously agreed to do so,” Paul wrote in a post on X on Tuesday. “Therefore, today we have issued a subpoena for him to publicly testify.”

The post included a photo of Paul appearing to sign the subpoena.

“We’ve been negotiating with him for material and for testimony,” Paul said in an appearance on CNBC on Tuesday. “This has gone on for some time. He slow-walked us and slow-walked us. Finally agreed to come in voluntarily … then last week he says he’s not coming in.”

“With this subpoena power, we will bring him in, unless he fights this in court,” Paul said.

The subpoena escalates a long-running conflict between Paul and Fauci over the origins of the COVID-19 pandemic. Paul has accused Fauci of covering up U.S. research at a lab in Wuhan, China, which the senator asserted caused the coronavirus outbreak.

Fauci served as director of the National Institute of Allergy and Infectious Diseases during the pandemic until 2022 and was a top medical adviser to both President Donald Trump and President Joe Biden.

The debate over the origin of COVID-19 has shifted in recent years. A U.S. intelligence analysis initially found insufficient evidence to determine whether the virus was leaked from a research lab in Wuhan. In January 2025, the CIA adjusted its assessment, according to an unnamed CIA representative who said the agency assesses “with low confidence that a research-related origin of the COVID-19 pandemic is more likely than a natural origin-based on the available body of reporting.”

During a 2024 House committee hearing, Fauci said he remained open to both possibilities. “I have repeatedly stated that I have a completely open mind to either possibility and that if definitive evidence becomes available to validate or refute either theory, I will readily accept it,” he said.

MSI previously reported that a former Fauci adviser was indicted in April on charges of allegedly concealing COVID-19 records, a development in the broader congressional scrutiny of pandemic-era decision-making. Read more.