President Biden’s ghostwriter could be the next witness in the hot seat before House impeachment investigators following the testimony Tuesday of a former special counsel, Robert Hur, who said the president willfully shared classified information with the writer despite not having the proper security clearance. 

The ghostwriter, Mark Zwonitzer, worked with Mr. Biden over the course of several months to craft his post-vice presidency memoir, “Promise Me, Dad,” the story of Mr. Biden’s year of struggle surrounding the death of his oldest son, Beau Biden. Mr. Zwonitzer also wrote Mr. Biden’s 2007 memoir, “Promises to Keep.”

During a recorded conversation between Messrs. Biden and Zwonitzer that was obtained by Mr. Hur, the two men were speaking at the president’s Virginia home in 2017 when Mr. Biden said he had “just found all the classified stuff downstairs.” Mr. Hur said this act would represent the “best case for charges” against Mr. Biden. 

Despite Mr. Hur finding that Mr. Zwonitzer was privy to some classified information as part of his writing for Mr. Biden, the president says no information was ever shared — a direct contradiction with his longtime writing partner’s account. 

“I did not share classified information,” Mr. Biden told reporters at the White House the night the special counsel report was released. “I did not share it with my ghostwriter — guarantee I did not.”

The testimony of Mr. Hur Tuesday directly contradicted the president’s statement, though. During his opening statement, Mr. Hur said that his investigation had uncovered evidence that Mr. Biden had knowingly kept classified information in his home and that Mr. Biden “read classified information aloud to his ghostwriter.”

There were instances in interviews with Mr. Zwonitzer where Mr. Biden failed to disclose classified information from his handwritten notes, which Mr. Hur says represents Mr. Biden’s knowledge that he could not share information with his ghostwriter — only to do it anyway at other points. 

“When Mr. Biden came to potentially classified material in his notebook entries, he appears to have sometimes stopped at or skipped over the potentially classified material,” the report states. “Zwonitzer also recalled Mr. Biden mentioning the need to be careful ‘because he was worried that there was a possibility that … some of this stuff could be classified.’”

Mr. Zwonitzer deleted some of the recordings of his interviews with the president after he learned of the appointment of Mr. Hur as special counsel. Mr. Zwonitzer later came clean, though, admitting to Mr. Hur’s office what he had done and allowing the FBI to search his hard drive. 

The FBI was able to recover all the audio recordings, but there were some sections of those recordings that were lost, the report states. Because Mr. Zwonitzer showed no “intent” to obstruct the special counsel investigator, Mr. Hur declined to prosecute. 

In his report to Congress, Mr. Hur stated that Mr. Biden retained classified national security documents related to American military, diplomatic, and intelligence issues in Afghanistan during the first few years of the Obama administration. Mr. Biden, who vehemently disagreed with President Obama’s decisions on the issue, “believed history would prove him right,” Mr. Hur alleged. 

That memoir made Mr. Biden a wealthy man for the first time in his life. According to Mr. Hur’s report, the then-former vice president was paid an $8 million advance in 2017 for the rights to the book. According to tax returns provided by the Biden campaign, Mr. Biden and his wife made more than $9.5 million in 2017 and nearly $4.6 million in 2018. 

The House Judiciary and Oversight committees have subpoenaed a transcript and audio recording of Mr. Zwonitzer’s interview with the special counsel’s office.