WASHINGTON — A recurring clash between the government’s top infectious disease doctor and a U.S. senator has erupted again on Capitol Hill, with each accusing the other of lying.

Dr. Anthony Fauci angrily confronted Republican Sen. Rand Paul of Kentucky in testimony before a Senate committee. Fauci rejected Paul’s insinuation that the U.S. helped fund research at a Chinese lab that could have sparked the COVID-19 outbreak.

Fauci spoke to the Senate Health, Education, Labor, and Pensions Committee, saying a study the senator mentioned referenced a different sort of virus entirely from the one responsible for the coronavirus outbreak.

“Senator Paul, you do not know what you’re talking about, quite frankly,” Fauci said. “And I want to say that officially. You do not know what you’re talking about.”

He added, “If anybody is lying here, senator, it is you.”

It was the latest in a series of clashes between Paul and Fauci about the origins of the virus that caused the global pandemic.