The chorus of calls for the impeachment of President Biden by congressional Republicans is growing in the wake of the release of an FBI form containing a confidential source’s corruption allegations against the president’s son, Hunter Biden, and his father when he was vice president.

Senator Grassley on Thursday released a FD-1023 form, which “our special agents use to record raw, unverified reporting from confidential human sources,” according to the FBI. For months, this particular form was the object of a tug-of-war between congressional Republicans and the FBI, which wanted to keep it confidential, saying that releasing it would potentially endanger the source. Mr. Grassley’s decision to release a partially redacted version of the form came as a surprise. 

Mr. Grassley said he decided to release the document so that people could “read this document for themselves without the filter of politicians or bureaucrats.”

The form contains the unverified statement of an anonymous “confidential human source,” or CHS, describing what he or she said were conversations overheard between two Ukrainian businessmen in the energy sector about how they employed Mr. Biden as a board member of the Ukrainian energy company, Burisma, in order to “protect” their interests. According to the informant, the two businessmen discussed paying two $5 million bribes, one to Hunter Biden and one to his father, who was then vice president and in charge of executing President Obama’s policy toward Ukraine.

Democrats have also released information that appears to contradict the claims made on the form, with the chief executive of Burisma reportedly saying, “No one from Burisma ever had any contacts with VP Biden or people working for him during Hunter Biden’s engagement.”

It has been public information for the last few years that during his father’s vice presidency, Hunter Biden was being paid about $60,000 a month to sit on Burisma’s board. The elder Mr. Biden has consistently denied ever getting involved in his son’s business affairs, with his supporters pointing out that during his vice presidency, the younger Mr. Biden was in a downward spiral, reeling from the death of his older brother, who had cancer, and in the throes of active addiction to cocaine and alcohol. 

Since taking control of the House of Representatives in 2023 and regaining subpoena power, three GOP House committees have been pursuing their own investigations of Mr. Biden’s family.

The FBI expressed concern over Mr. Grassely releasing the document in a statement to Insider following the release of the form, saying that “at minimum,” it “unnecessarily risks the safety of a confidential source.”

In response to the release of the form by Mr. Grassely, and following a House Oversight Committee hearing on Wednesday in which two IRS whistleblowers alleged that Department of Justice officials slow-walked the Hunter Biden probe, House Republicans are leveling new calls for the impeachment of President Biden. During the hearing, Congresswoman Marjorie Taylor Greene also displayed nude photos of the younger Mr. Biden.

“Most corrupt family to ever live in the White House,” Congressman Jim Banks wrote on Twitter. “Impeach.”

Congresswoman Lauren Boebert wrote, “Read and understand just how deep the corruption goes. Biden should be thrown out of office. Impeach.”

House Republicans have previously pushed for an impeachment of Mr. Biden, most recently over the administration’s immigration and border policy.

The two representatives join members like Congresswoman Anna Luna, who said she was convinced by “evidence and testimony” that the House needed to impeach Mr. Biden.

In a statement responding to the document’s release, the ranking member of the House Oversight Committee, Jamie Raskin, said, “Even Senator Johnson recognized these allegations may have been fabricated out of thin air.”

“Releasing this document in isolation from explanatory context is another transparently desperate attempt by Committee Republicans to revive the aging and debunked Giuliani-framed conspiracy theories and to distract from their continuing failure to produce any actual evidence of wrongdoing by the President — even at the cost of endangering the safety of FBI sources,” Mr. Raskin said.

The White House has denied all of the allegations leveled in the 1023 form, with spokesman Ian Sams saying, “These claims have reportedly been scrutinized by the Trump Justice Department, a Trump-appointed U.S. attorney, and a full impeachment trial of the former President that centered on these very issues, and over and over again, they have been found to lack credibility.”

“It is remarkable that congressional Republicans, in their eagerness to go after President Biden regardless of the truth, continue to push claims that have been debunked for years and that they themselves have cautioned to take ‘with a grain of salt’ because they could be ‘made up,’” Mr. Sams said in a statement.

Speaker McCarthy has not yet weighed in on the renewed calls for impeachment. When members of the House pushed for impeachment earlier this summer, though, he was able to sideline the issue, sending the articles to the committee to be reviewed.