House Democrats on Wednesday released emails in which Jeffrey Epstein wrote that President Trump had “spent hours at my house” with one of Mr. Epstein’s victims, among other messages that suggested that the convicted sex offender believed Mr. Trump knew more about his abuse than he has acknowledged.

Mr. Trump has emphatically denied any involvement in or knowledge of Mr. Epstein’s sex-trafficking operation. He has said that he and Mr. Epstein, the disgraced financier who died by suicide in federal prison in 2019, were once friendly but had a falling out.

But Democrats on the House Oversight Committee said the emails, which they selected from thousands of pages of documents received by their panel, raised new questions about the relationship between the two men. In one of the messages, Mr. Epstein flatly asserted that Mr. Trump “knew about the girls,” many of whom were later found by investigators to have been underage. In another, Mr. Epstein pondered how to address questions from the news media about their relationship as Mr. Trump was becoming a national political figure.

In a statement denouncing the release of the messages, Karoline Leavitt, the White House press secretary, identified the victim mentioned in one of them as Virginia Giuffre, who died by suicide in April and had said that she did not think that Mr. Trump had participated in the sexual abuse of minors at Mr.