President Trump’s allies have promoted claims of corruption aimed at the former vice president’s son in an effort to damage the Biden campaign.
Some reporters withheld their bylines and questioned the credibility of an article that made the tabloid’s front page on Wednesday.
The report delivered on Wednesday appeared to be little more than a rehashing of unproven allegations that echoed a Russian disinformation campaign.
Democrats demanded an F.B.I. briefing. They were concerned about a potential Russian-linked effort to interfere in the election by using a Senate panel to advance smears against Joe Biden, officials said.
Republicans are using their Senate majority to try to uncover evidence of wrongdoing that President Trump believes is pivotal to his party’s chances in November.