Sen. Chuck Grassley, R-Iowa., along with House Oversight Committee Chairman James Comer announced Wednesday that a whistleblower is claiming the DOJ and FBI possess a file describing an alleged criminal scheme involving then-Vice President Joe Biden and a foreign national.

"This comes from a credible and unclassified whistleblower disclosures of this possible criminal activity when Biden was vice president," Grassley told Fox News' Sandra Smith on "America Reports."

Rep. James Comer, R-Ky., issued a congressional subpoena Wednesday, that seeks the specific FBI document.

FEDERAL PROSECUTORS NEAR DECISION ON HUNTER BIDEN PROBE: REPORT

According to a press release from Comer's office Wednesday, Grassley said he believes "the FBI possesses an unclassified internal document that includes very serious and detailed allegations implicating the current President of the United States."

James Comer

FILE: House Oversight and Accountability Committee Chairman James Comer, R-Ky. (AP Photo/J. Scott Applewhite)

In Comer and Grassley's letter to the DOJ and FBI, they write that the agency possesses an "unclassified FD-1023 form that describes an alleged criminal scheme involving then-Vice President Biden and a foreign national relating to the exchange of money for policy decisions."

"It really boils down to my traditional oversight of government, particularly to see if the executive branch is doing the work that they're supposed to be doing," said Grassley. 

"So the Justice Department, the FBI needs to come clean to the American people, what they did with the document, because we know the document exists from very credible whistleblower information that we got. We really need to know what steps did the Justice Department and FBI take to investigate and to vet the document to determine if it's accurate or not? And did the Justice Department and the FBI follow normal investigative procedures or did they let political calculations interfere?" 

2011 EMAILS REVEAL HUNTER BIDEN HELPED BUSINESS ASSOCIATES GET ACCESS TO VP BIDEN, TOP AID

"If the Justice Department and the FBI have any hopes of redeeming their once trusted position with the American people, Garland and Wray must answer this subpoena and tell us what they're doing with this information that we think is very credible based upon what whistleblowers are telling us," said Grassley.  

Sen. Chuck Grassley

US Republican Senator from Iowa Chuck Grassley. (Photo by OLIVIER DOULIERY/AFP via Getty Images)

Grassley said he "hopes" the FBI will cooperate with the investigation, and in doing so will "enhance" their credibility. 

He added that the American people deserve transparency from the FBI.

VP BIDEN'S OFFICE TRIED TO QUASH BLOOMBERG STORY ABOUT HUNTER BIDEN AT HIS FIRM'S REQUEST, EMAILS SHOW

Grassley has been investigating Hunter Biden's business dealings and any alleged involvement by the elder Biden in the Senate, since 2019.

CLICK TO GET THE FOX NEWS APP

Fox News' Brooke Singman contributed to this report.