Warren, a Massachusetts Democrat, leveled the accusation after Tapper asked her to comment on a series of controversial remarks made by Office of Management and Budget Director Mick Mulvaney, whom Trump tapped to also serve as interim director of the Consumer Financial Protection Bureau in November.

In a speech to banking executives on Tuesday, Mulvaney said when he was in Congress, "if you were a lobbyist who never gave us money, I didn't talk to you. If you were a lobbyist who gave us money, I might talk to you."

Mulvaney is a former Republican congressman from South Carolina.

He went on to add that he would meet with anyone who was a constituent. "If you came from back home and sat in my lobby, I talked to you without exception regardless of the financial contributions," he said.

Warren slammed the remarks, saying it shows that Trump's is the "most corrupt administration ever."

"I mean, come on, this is a man who stood up in front of 1,300 people and said, 'the congressman will listen to you, but only if you pay,'" she said on CNN's "The Lead with Jake Tapper." "That's called pay-to-play, and that's just another way of saying, 'this joint runs great for those who can hire armies of lobbyists and lawyers and have them make big campaign contributions, but not here for real people.'"

On Mulvaney, Warren said, "He's so corrupt that he was willing to just lay it all out there in front of everyone. He said, 'I am a government official who pays attention to those who pay me.' If that's not corruption, I don't know what the definition of corruption is."

A request for comment on Warren's remarks was not immediately returned by the CFPB.