(The Hill) – Congressional Republicans are vowing to keep investigating Anthony Fauci even after he steps down from his government roles at the end of the year.

“Retirement can’t shield Dr. Fauci from congressional oversight,” House Committee on Oversight and Reform ranking member James Comer (R-Ky.), said in a statement. Comer would likely become the chair of the committee in a Republican majority.

Fauci, who is chief medical adviser to the president and has spent decades as director of the National Institute of Allergy and Infectious Diseases, announced Monday that he would step down from his positions in the Biden administration after more than a half century in government. Fauci said he is not retiring, and plans to “pursue the next phase” of his career.

Republicans have already launched probes into the origins of the coronavirus and are planning further investigations and hearings if they win the majority in November, including possibly digging into Fauci’s own records.

“Fauci’s resignation will not prevent a full-throated investigation into the origins of the pandemic. He will be asked to testify under oath regarding any discussions he participated in concerning the lab leak,” tweeted Sen. Rand Paul (R-Ky.), who has gotten into heated exchanges with Fauci during Senate hearings and is in line to become chair of the Senate Health, Education, Labor and Pensions Committee if Republicans win the Senate majority.

Fauci, who became the most public face of the federal government’s COVID-19 response, also became a top target of Republicans. He publicly disagreed with former President Trump over the level of threat the virus posed and unproven treatments, and he was among the leading voices calling for mitigation measures.

“In January, a GOP Congress should hold Fauci fully accountable for his dishonesty, corruption, abuse of power, and multiple lies under oath,” tweeted Sen. Ted Cruz (R-Texas). “Never in our nation’s history has one arrogant bureaucrat destroyed more people’s lives.”

Republicans have pushed the theory that the novel coronavirus originated in a laboratory in Wuhan, China, and that U.S. funding went to “dangerous” research on coronaviruses at the same lab.

Two studies released last month point to the theory that the virus was transmitted from animals to humans, likely in a Wuhan market, though some scientists think the idea that it escaped from a lab warrants further investigation. The U.S. intelligence community has said the virus was not created as a bioweapon.

Additional investigation is unlikely to happen without cooperation from China.

“Emails obtained by Oversight Committee Republicans reveal what Dr. Fauci said publicly about COVID origins was very different than what was said privately,” Comer said in his statement. “Dr. Fauci was warned by top scientists early on that the virus looked genetically manipulated and likely leaked from the Wuhan lab. Despite these facts, Dr. Fauci dismissed these ideas in public as conspiracy theories. We need to know if Dr. Fauci concealed anything from government officials in order to shield the NIH’s cozy relationship with EcoHealth Alliance, a grantee that awarded taxpayer funds to the Wuhan lab to conduct dangerous research on bat coronaviruses. The American people deserve transparency and accountability about how government officials used their taxpayer dollars, and Oversight Committee Republicans will deliver.”

Some Republicans suggested that Fauci timed his departure from government to avoid dealing with a GOP majority taking power next year.

“Dr. Fauci is conveniently resigning from his position in December before House Republicans have an opportunity to hold him accountable for destroying our country over these past three years. This guy is a coward,” tweeted Rep. Andy Biggs (R-Ariz.), a former chair of the House Freedom Caucus.

Rep. Chip Roy (R-Texas) tweeted in reaction to Fauci’s departure: “Interesting timing… #COVIDHearings.”

Peter Staley, a longtime HIV/AIDS activist and friend of Fauci, responded to an assertion from Donald Trump Jr. that Fauci is trying to avoid oversight by leaving the government at the end of the year. 

“Tony knows full well this doesn’t preclude his being Benghazied by your fellow numbnuts in the House. He’s ready for it, and fully armed with the truth,” Staley tweeted.