Two senior Republicans claimed Wednesday that the FBI had been holding a report detailing an alleged scheme in which then-Vice President Joseph R. Biden accepted money for making policy decisions on behalf a “foreigner” on behalf of Biden.

Sen. Charles E. Grassley of Iowa, and Rep. James Comer of Kentucky, both Republicans, claimed that their information came from “highly credible whistleblowers” who referred to a confidential report on human sources which the FBI had been using for years.

The report did not specify when or which country was involved in the alleged deal.

The FBI did claim that the information they obtained was sufficiently detailed to be verified.

According to these disclosures, we have learned that the Department of Justice and the Federal Bureau of Investigation both possess an unclassified FD-1023 document that describes a criminal scheme involving Vice President Biden at the time and a foreigner involving the exchange of money in return for policy decisions. The document is said to include a detailed description of the criminal scheme and its purpose.

The lawmakers stated that it was unclear, however, what, if anything, steps were taken to investigate this matter.

The FBI collects information about human sources using form 1023.

Mr. Comer issued a subpoena as the chairman of the House Oversight and Accountability Committee ordering FBI Director Christopher A. Wray, to hand over the form before May 10.

The FBI confirmed that it had received the subpoena and letter but declined to make any further comments.

The FBI has had a tough time, as it pursued Donald Trump both as a presidential candidate and a campaigner. This included lying to a judge to obtain a warrant for surveillance on a Trump candidate and pursuing the now discredited Steele dossier.

Mr. Grassley in particular has criticised the FBI’s decision-making.

He and Mr. Comer have said that they are investigating how the FBI handled the report about Mr. Biden.

The DOJ and FBI have valuable, verifiable data that you have not disclosed to the American public. Congress will conduct an independent, objective review of the matter free from any influence by these agencies,” they stated.

The subpoena issued by Mr. Comer covers “all FD-1023 documents, within any open, restricted or closed case files created or modified after June 2020 that contain the term ‘Biden’, as well as all attachments and supporting documents for those FD-1023 form.”

The chairman of the oversight committee is already conducting a wide-ranging investigation into Biden’s family and their dealings.

The committee is investigating the role of Hunter Biden, the son of the president, on the board Burisma, an Ukrainian natural gas company. His father served as vice president during the Obama administration.

Comer claimed that he had obtained financial records in March showing that members of the President’s family, through Biden family friends, received money from an energy company in China from 2015 to 2017.

Rob Walker, a friend of the family and a business associate, received $3 million in compensation from State Energy HK Ltd. James Gilliar was another friend who collected $1.1 million.

Comer claimed that they sent money to Hunter Biden as well as the president’s brother James Biden. They also sent money to Hallie Biden who is the daughter-in law of the president.

Last month, Comer stated that he also was investigating six other Biden relatives.

He said that the Oversight Committee would continue to investigate additional bank records in order to track the Bidens and their tangled webs of financial transactions. This will help determine whether the Bidens have been targeted by foreign actors, or if a national threat exists.

Democrats on the oversight panel say that Mr. Comer misrepresents, or fabricates, his investigation findings.

Mr. Biden said that he did not get involved in the family business while he served as vice president.