Paul uttered the name in a question that U.S. Supreme Court Chief Justice John Roberts had earlier declined to read as the presiding officer of the trial. The Senate was not holding impeachment proceedings when Paul spoke on Tuesday.

The Kentucky senator also displayed the question on a poster board positioned nearby. It alleged that an official at the White House National Security Council (NSC) conspired with a Democratic staffer of the House Intelligence Committee, which spearheaded the impeachment inquiry.

But Paul first pointed out that the question, while using the name of an NSC official reported by conservative media to be the whistleblower, did not actually identify the person as such.

"They made a big mistake not allowing my question. My question did not talk about anybody who was a whistleblower. My question did not accuse anybody of being a whistleblower," Paul said. "It did not make a statement believing someone was a whistleblower. I simply named two people's names."