Internal Revenue Service investigator Gary Shapley, who came forward along with Joseph Ziegler as a whistleblower in the Hunter Biden tax probe, told Fox News Special Counsel David Weiss' credibility has been rendered "nonexistent" and Attorney General Merrick Garland's behavior may warrant its own probe.

Shapley said that Weiss, the Trump-appointed but Biden-holdover U.S. Attorney for the District of Delaware, was reportedly found to have not planned to bring charges against Hunter Biden in his investigation until Shapley and Ziegler went public about the case.

Questions also arose from Weiss' reported closeness with then-Delaware Attorney General Beau Biden – the president's elder, now-deceased son, a decade ago.

"For David Weiss to continue on in this as a special counsel's investigation just raises so many questions for the American people," Shapley told "The Story."

IRS WHISTLEBLOWER'S ATTORNEY: DAVID WEISS HAS GOT TO GO, CITING BEAU BIDEN CONNECTIONS, BOMBSHELL REPORTS

Special Counsel David Weiss

U.S. Attorney for the District of Delaware David Charles Weiss. (Fox News screenshot)

"His credibility is and is just nonexistent at this point. He played his cards," he added.

Weiss and the Wilmington federal prosecutor's office along with the DOJ never anticipated they'd be scrutinized for their reported machinations behind the scenes, Shapley said.

"And they're being held accountable now. And I hope that Congress continues to pursue that and push it forward to ensure that the American people will be confident that our Department of Justice is equal," he said.

To that end, Shapley suggested such scrutiny should rise all the way to the top of the DOJ with Garland as well as Weiss.

"What we really need is … a special counsel to investigate this investigation – And that includes the actions of U.S. Attorney Weiss, Attorney General Garland, the statements made to Congress, the letters sent to Congress over and over again as information comes out has proven that what they told the American people, what they told the Congress was not accurate," Shapley said.

Congressional Republicans and other observers have claimed there have been conflicting narratives as to whether Weiss was given the ability to bring charges against Hunter Biden in Los Angeles and the District of Columbia, while other claims arose that the prosecutors in both jurisdictions, Martin Estrada and Matt Graves respectively, turned him down.

HUNTER BIDEN CASE MOVE TO LOS ANGELES EVIDENCE THE FEDS FOUND SOMETHING NEW: DERSHOWITZ

IRS Whistleblower X Joseph Ziegler and Gary Shapley

Gary Shapley and Joseph Ziegler (BRENDAN SMIALOWSKI/AFP via Getty)

Garland ultimately named Weiss special counsel in the case earlier this month, which some said called into question whether he had such acclaimed free prosecutorial reign in the first place, to bring charges outside the First State.

Others meanwhile, claimed Garland violated federal regulations in naming Weiss – a sitting federal prosecutor – as special counsel.

In a recent Fox News Opinion column, legal analyst Gregg Jarrett cited 28 CFR 600.3, which states a special counsel shall be selected from outside the United States government. Jarrett argued in the column that Weiss' new appointment is therefore a "farce."

Previous special or independent counsels Kenneth Starr, Robert Mueller and Robert Hur were all either out of government or resigned at the time of their naming to the post.

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On Fox News, Shapley said the recent developments are another example of why he decided to go to Congress with his concerns.

"I came forward for the American people and I put myself at risk for the American people. And, you know, at the end of the day, they need to be confident that this investigation is actually looked at independently and fairly," he said.

"I would be fully onboard to assist moving forward, whether it was with Mr. Weiss or with a different special counsel," he added, when asked if he or Ziegler would welcome being invited back into the investigation.

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