WATCH: Fauci invokes 5th Amendment, declining to answer questions in GOP-led hearing on COVID-19

Dr. Anthony Fauci, a former top official and scientist at the National Institutes of Health, said he would invoke the Fifth Amendment and decline to answer questions during a hearing Wednesday held by the Senate Committee on Homeland Security and Governmental Affairs.

Watch the clip in the video player above.

"Although it pains me to do so, because of the respect I have for the legislative branch of government, and my decades-long record of cooperating with Congress, under the advice of my attorneys I will invoke my right under the Fifth Amendment of the Constitution to refrain from answering your questions," Fauci said.

WATCH LIVE: Fauci invokes 5th Amendment in GOP-led hearing about COVID-19 origins

Committee chair Sen. Rand Paul, R-Ky., subpoenaed Fauci to appear at the hearing aimed at again questioning him on the origins of the coronavirus.

Fauci described Paul as having an "unhinged obsession" with him and said "any reasonable person" would come to the same conclusion about refusing to answer the committee's questions.

"The sole reason he is calling me before this committee is to get me to say something, anything, that could vindicate his repeated public pledges that I end up in his words, quote, behind bars," Fauci said.

Paul released more than a thousand pages of Fauci's pandemic-era diary over the weekend.