A marathon closed-door interview of President Trump's former Ukraine envoy tore apart Democrats' claims of a quid pro quo between the two governments, House Foreign Affairs Committee member Scott Perry, R-Pa., claimed on Thursday.

Former envoy Kurt Volker was an outstanding witness who proved Trump did not engage in such an unethical activity with Ukrainian President Volodymyr Zelensky, Perry asserted Thursday on "The Story."

"You really couldn't have a more professional and more credible witness -- and more knowledgable about Ukraine," he said.

"I would call Ambassador Volker the star witness named in the so-called whistleblower's report. Everything he said unsubstantiated this claim of a quid pro quo."

EX-UKRAINE ENVOY VOLKER MEETS WITH LAWMAKERS AMID IMPEACHMENT PROBE, AS TEXTS REVEAL 'QUID PRO QUO' DISPUTE

In the lead-up to the nine-and-a-half-hour interview of Volker by the House Foreign Affairs, Intelligence and Oversight Committees, Trump had been accused of pressing Ukraine to investigate Hunter Biden in order to receive millions of dollars in frozen military aid.

Perry told host Martha MacCallum that at one point in the hearing, Volker was asked to read from text messages between himself and other American officials or diplomats.

One text read that Trump, "made it crystal-clear there will be no quid pro quo whatsoever," the central Pennsylvania lawmaker recalled.

"And that really told the story," he added.

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Volker had been called to Capitol Hill after a whistleblower's complaint concerning the Trump-Ukraine phone call mentioned him as having allegedly played a role in Trump lawyer Rudy Giuliani’s investigations connected to Ukraine. He resigned soon after the complaint was made public last week.

House Intelligence Committee Chairman Rep. Adam Schiff, D-Calif., told reporters Thursday afternoon that he would not yet comment on Volker's testimony, but offered some words of criticism for Trump. Schiff claimed that by "suggesting, urging a foreign country to interfere in our presidential election," Trump showed that after two years of Robert Mueller's Russia investigation, "he feels he can do anything with impunity."

Fox News' Ronn Blitzer and Mike Emanuel contributed to this report.