A close business associate of Hunter Biden, Eric Schwerin, exchanged dozens of e-mails with President Biden throughout 2014, around the same time that Mr. Biden fils was appointed to a lucrative seat on the board of the Ukrainian energy conglomerate Burisma and his father, then the vice president, was putting pressure on Ukraine to fire its top prosecutor.

While the contents of the messages are not known, the White House has maintained that Mr. Schwerin has only ever helped Biden family members with anodyne financial issues such as filing taxes. 

Mr. Schwerin and the elder Mr. Biden exchanged e-mails 54 times in 2014, with many of those messages being sent around the time of his visits to Ukraine. All told, five messages were sent in the lead-up to his first visit to the country, and 27 messages were sent between June and the then-vice president’s November trip to Ukraine. The first son had been hired along with his friend Devon Archer to serve on Burisma’s board of directors in April 2014, for which they were paid handsomely. 

The e-mails were first reported by NBC News. 

At a September interview with the Oversight Committee, Mr. Schwerin denied that Mr. Biden was ever involved with his son’s businesses. Republicans on the committee described that interview as an “informal” conversation and later subpoenaed Mr. Schwerin. He appeared for a sworn deposition on Tuesday. 

The top Democrat on the committee, Congressman Jamie Raskin, described the September interview with Mr. Schwerin as a fishing expedition that yielded no results for the GOP majority. 

“The Committee’s interview of Eric Schwerin, who served as then-Vice President Biden’s bookkeeper from 2009 to 2017, established that he never saw any transactions into or out of the then-Vice President’s bank account related to business conducted by any Biden family member,” Mr. Raskin said. “None of the [suspicious activity reports] allege, or even suggest, any potential misconduct by President Biden, nor do they show any involvement by President Biden in Hunter Biden’s business relationships. None of the bank records have shown any payments to President Biden, as even Republicans have conceded.  There is no evidence of any wrongdoing by the President.”

A spokesman for the White House Counsel’s office did not immediately respond to a request for comment. 

While the White House maintains that Mr. Schwerin was nothing more than a bookkeeper, he was undeniably intimately involved with some of the younger Mr. Biden’s foreign business dealings. From 2002 to 2008, Mr. Schwerin worked with Mr. Biden, Archer, and Secretary Kerry’s stepson, Chris Heinz, the ketchup heir and son of the late Senator Heinz, at Rosemont Seneca Partners.

Fox News previously reported that Mr. Schwerin had visited the vice president’s official residence, the Naval Observatory, a total of 19 times during the Obama–Biden administration. 

Mr. Obama twice appointed Mr. Schwerin to the Commission for the Preservation of America’s Heritage Abroad, first in 2015 and then again in 2017. Mr. Schwerin’s involvement with the Bidens was long-standing and very intimate, according to one member of the family. The first son’s ex-wife, Kathleen Buhle, disclosed in a 2022 memoir that Mr. Schwerin “managed almost every aspect of our financial life” during his and Mr. Biden’s friendship and partnership. 

Also appointed to the Commission for the Preservation of America’s Heritage Abroad was wealthy Biden donor Elizabeth Hirsh Naftali. She has been subpoenaed by the Oversight Committee, which wanted to know more about her purchases of artwork painted by Hunter Biden.

The younger Mr. Biden also noted in a 2015 e-mail that Mr. Schwerin had been asking him for an appointment to one of the many pseudo-ceremonial presidential commissions “the day after the 2008 election.”

The elder Mr. Biden has refused to turn over many of the e-mails from his time as vice president. The Oversight Committee has disclosed that there are thousands of e-mails from several different e-mail accounts that used aliases so Mr. Biden could communicate with friends and family — including his son, Mr. Schwerin, and other family business associates.