An election-year investigation by Senate Republicans into corruption allegations against Joseph R. Biden Jr. and his son, Hunter, involving Ukraine found no evidence of improper influence or wrongdoing by the former vice president, closing out an inquiry its leaders had hoped would tarnish the Democratic presidential nominee.

The investigation found that Hunter Biden had “cashed in” on his father’s name to close lucrative business deals around the world. It also concluded that his work for Burisma Holdings, a Ukrainian energy company then mired in a corruption scandal, while the former vice president was directing American policy toward Kyiv had given the appearance of a conflict of interest and alarmed some State Department officials.

But an 87-page report summing up the findings, released jointly on Wednesday by the Senate Homeland Security and Finance Committees, contained no evidence that the elder Mr. Biden improperly manipulated American policy toward Ukraine or committed any other misdeed. In fact, investigators heard witness testimony that rebutted those charges.

The homeland security panel’s Republican chairman, Senator Ron Johnson of Wisconsin, had made little secret of his political ambitions for his report, boasting for weeks that his findings would demonstrate Mr. Biden’s “unfitness for office.” Instead, the result delivered on Wednesday appeared to be little more than a rehashing six weeks before Election Day of unproven allegations that echo an active Russian disinformation campaign and have been pushed by Mr. Trump.

In the days before its release, Mr. Johnson conceded in an interview that there would be no “massive smoking guns,” saying that there was “a misconception on the part of the public that there would be.”

The report’s primary conclusions, though, were largely the ones Mr. Johnson and his investigative partner, Senator Charles E. Grassley, Republican of Iowa, had made before they began their work, with some new details from State Department and financial transaction reports.

Hunter Biden’s position “hindered the efforts of dedicated career-service individuals who were fighting for anticorruption measures in Ukraine,” the Republicans wrote. They did not clarify the nature of that hindrance beyond saying that the situation had been “awkward” for career State Department officials, who “were required to maintain situational awareness of Hunter Biden’s association with Burisma.”

It was also filled with details that emphasized the unseemly appearance created by the younger Mr. Biden’s involvement with Burisma, given his father’s position. Section 8 of the report was entitled “HUNTER BIDEN: A SECRET SERVICE PROTECTEE WHILE ON BURISMA’S BOARD.”

“What the chairmen discovered during the course of this investigation is that the Obama administration knew that Hunter Biden’s position on Burisma’s board was problematic and did interfere in the efficient execution of policy with respect to Ukraine,” the report said.

The Trump campaign quickly promoted the “explosive new revelations,” zeroing in on financial records obtained by the senators that showed Hunter Biden received large sums of money from foreigners while his father was in office.

All 10 witnesses interviewed by investigators, however, testified that neither Mr. Biden nor anyone else had altered American policy because of his son.

“Every witness stated that Hunter Biden and his associates had no role in the formulation of U.S. policy, that Hunter Biden’s role did not influence U.S. foreign policy decisions, and that Vice President Biden carried out U.S. foreign policy in the interest of the United States.”

The lack of meaningful new information and the overlap with a Russian disinformation campaign that American intelligence officials have warned is designed to denigrate Mr. Biden helped fuel allegations that Mr. Johnson had abused his Senate powers to aid Mr. Trump’s re-election campaign — and in so doing, had aided Moscow.

You can read the full report here.