Tuesday is the deadline for the FBI director, Christopher Wray, to hand over a document that’s said to detail alleged corruption by President Biden while he was serving as vice president, but for weeks Mr. Wray has shown little interest in complying with Republican investigators probing the Biden family’s years of murky financial dealings. 

The chairman of the powerful House Oversight Committee, Congressman James Comer, asked for the letter in early May, but Mr. Wray and the FBI have so far declined to turn it over. 

Shortly after Mr. Comer threatened to hold Mr. Wray in contempt of Congress on May 25, the director agreed to a phone conversation that will be held Wednesday, after the Tuesday deadline has passed. It is unclear if this will just be a courtesy call, or if the director could be substantively engaging with House Republicans on the issue of congressional oversight. 

On Tuesday morning, Speaker McCarthy raised the stakes for Mr. Wray. “If he misses today’s deadline to turn over subpoenaed documents to Congress, I am prepared to move contempt charges against him,” Mr. McCarthy said on Twitter. 

The new disclosure details an alleged $5 million payment that a whistleblower says was directed to the future president when he was vice president. The whistleblower came forward on June 30, 2020, in a letter sent to Senator Grassley, who shortly thereafter launched his own investigation into Mr. Biden’s troubled son, Hunter, and how the Biden family may have profited from Hunter’s years of influence peddling and trading on the Biden family name.

Observers have speculated that the alleged “bribe” in question could be related to Hunter Biden’s involvement with the Ukrainian energy company Burisma, which paid him handsomely to serve on its board for five years, despite having no experience in the energy sector.

Just 17 days before that disclosure was made to Mr. Grassley, Ukrainian officials held a press conference in Kyiv to report that someone attempted to pay $5 million in a bribe to end an investigation into the company’s founder, Mykola Zlochevsky. At the time, Ukraine’s anti-corruption office denied that the alleged bribe had any connections to the Bidens, according to Reuters.

Speaking with Fox News on Thursday, Mr. Comer said that the whistleblower report detailing the alleged bribe is part of a pattern with the president’s family. “The reason that I think it’s very credible is this claim was made years before anyone knew about these different shell companies and knew exactly what the Biden family did in counties like Romania and China to get money,” he said. 

Mr. Comer originally requested that the FBI turn over the whistleblower report on May 3. The subpoena asked the FBI to release an unclassified version of the report that “allegedly details an arrangement involving an exchange of money for policy decisions.”

“The information provided by a whistleblower raises concerns that then-Vice President Biden allegedly engaged in a bribery scheme with a foreign national,” Mr. Comer wrote in a statement at the time. “The American people need to know if President Biden sold out the United States of America to make money for himself.”

When the FBI failed to turn over the information by the deadline — May 10 — Mr. Comer sought a meeting with Mr. Wray, who declined. Briefings on the issue given to the Oversight Committee staff by the FBI have left Mr. Comer wanting. 

“The FBI’s refusal to produce this single document is obstructionist,” Mr. Comer wrote to Mr. Wray on Wednesday before his threat to hold him in contempt. “Public corruption, influence peddling, federal ethics/financial disclosure regulations, and national security matters are directly within the purview of the Committee’s oversight authorities.”

Should Mr. Wray be held in contempt of Congress, it is likely that nothing will come of it. Following such resolutions, the Department of Justice is authorized to pursue criminal charges against those individuals. President Trump’s former chief strategist, Steve Bannon, has been convicted of defying a subpoena, for which he was held in contempt. 

Mr. Grassley has previously investigated the nature of Hunter Biden’s foreign business deals, which allegedly also involved the president’s younger brother, James (who like Hunter Biden has long been accused of trading on the Biden family name to make money). In October 2022, Mr. Grassley’s Senate office sought information related to the Biden family’s involvement with business entities tied to the Chinese Communist Party. “The Justice Department’s and FBI’s continued silence on these matters is deafening and further erodes their credibility,” Mr. Grassley wrote at the time. 

“Simply put, enough is enough — the Justice Department and FBI must come clean to Congress and the American people with respect to the steps they have taken, or failed to take, relating to the Hunter Biden investigation,” he added.

Before that, Mr. Grassley had been conducting his own investigations into Hunter Biden while serving as chairman of the Senate Judiciary Committee, though it was not an official committee investigation. Before the 2020 presidential election, Mr. Grassley’s office sent a number of financial records to the United States attorney for the district of Delaware, David Weiss, who is still looking into the younger Mr. Biden’s business and tax records. 

While congressional Republicans have long focused on Hunter Biden as the nexus of possible payment schemes to the family, the whistleblower report being sought by Messrs. Comer and Grassley could be the first instance of a whistleblower directly tying the sitting president to foreign entities.