President Trump and his campaign on Wednesday revived allegations of wrongdoing against Democratic nominee Joe Biden and his son Hunter Biden, citing a New York Post story that has drawn skepticism over its sourcing and findings.

The Post story, published on Wednesday morning, alleges that Hunter Biden used his influence to connect a Ukrainian businessman, and fellow board member at the gas company Burisma, with his father when he was vice president.

Trump and his allies were quick to promote the story as evidence of corruption by the Bidens, but the allegations prompted questions about why the material was being released just 20 days before an election where Trump is trailing his Democratic rival in the polls.

The president on Wednesday decried the Bidens as "grifters and crooks," calling the Post's findings a "major scandal" in an interview with Newsmax TV.

"The New York Post, they've done great reporting," Trump said. "It's serious stuff. They've got 'em cold, and the news protects them because they're in on the deal, probably."

The Trump campaign denied that it had any involvement in providing the documents to the Post, but was still eager to try and turn it into a major storyline. The campaign launched a new 30-second ad highlighting Hunter Biden's foreign business dealings and convened a call with reporters to discuss the story just hours after it was published.

"If the New York Post story is true, we now know Joe Biden lied to the American people and he lied repeatedly to all of you. Biden has claimed he has no knowledge of his son’s business schemes," said Pam Bondi, a former Florida attorney general who was part of the president's impeachment defense team earlier this year.

The Post story hinges on an email message from Vadym Pozharskyi, an adviser to Ukrainian gas company Burisma, thanking his colleague Hunter Biden for "giving an opportunity to meet your father and spent some time together.”

The origins of the material are unclear. The Post reported that the email was obtained from a hard drive after a computer was dropped at a Delaware repair shop in April 2019.

The unnamed store owner could not identify the individual who dropped it off as Hunter Biden, but nonetheless notified federal authorities about the computer, which was reportedly seized by the FBI last December.

The Post said the owner made a copy of the hard drive before turning it over and also provided it to an attorney for Rudy Giuliani, who is Trump's personal lawyer and was deeply involved with a Ukrainian official later determined to be a Russian agent in digging up dirt on Joe Biden earlier this year.

Joe Biden’s campaign responded on Wednesday by saying numerous investigations have all concluded there was “no wrongdoing" by the former vice president.

“Investigations by the press, during impeachment, and even by two Republican-led Senate committees whose work was decried as 'not legitimate' and political by a GOP colleague have all reached the same conclusion: that Joe Biden carried out official U.S. policy toward Ukraine and engaged in no wrongdoing. Trump Administration officials have attested to these facts under oath," Biden campaign spokesman Andrew Bates said in a statement.

The campaign accused the Post of failing to ask for comment on "critical elements" of the story, including the involvement of Giuliani.

"Moreover, we have reviewed Joe Biden’s official schedules from the time and no meeting, as alleged by the New York Post, ever took place," Bates said.

The president's allies at times appeared unwilling to fully stand behind the Post story.

Bondi repeatedly qualified her statements by citing the Post or noting that the allegations would be damaging "if true."

Sen. Ron Johnson (R-Wis.), whose Senate Homeland Security and Governmental Affairs Committee recently concluded an investigation into the effects Hunter Biden's work had on Obama administration policy, said the Post story “raises more questions.”

“There are so many red flags about the Biden family trying to cash in on the Vice President’s position that it can be hard to keep them straight. Today’s report raises more questions that must be resolved,” Johnson said in a statement. “What we know for a fact is that Hunter Biden took millions of dollars from foreign nationals including, the wife of the former Mayor of Moscow, people tied to the Chinese Communist Party and other unsavory characters. Joe Biden needs to finally come clean and tell the truth to the American people about all of these issues, and he needs to do it now.”

Earlier in the day, a spokesman for Johnson said the panel had received a whistleblower complaint and was looking into the materials published by the Post, but noted that officials are "attempting to validate the information."

In an unusual step, a Facebook spokesman said the platform would limit the distribution of the Post story while it underwent a fact-check. Twitter later blocked users from sharing the link to the Post story, saying it had been identified as "potentially harmful."

Attempts to elevate the article are part of a broader effort by the Trump campaign to make Hunter Biden's business dealings a central feature of its attacks on Joe Biden dating back to the Democratic primary.

The president's request for the Ukrainian president to "do us a favor" and look into potential wrongdoing involving the Bidens during a 2019 phone call sparked off an investigation that ended with Trump being impeached by the House and acquitted by the Senate on charges of abuse of power and obstruction of Congress.

Trump and his campaign have repeatedly tried to make the attacks against Hunter Biden stick, selling shirts that read "where's Hunter" and bringing his business dealings up during the first presidential debate.

Hunter Biden joined the board of Burisma Holdings, a natural gas giant in Ukraine, in 2014. The company's founder was under investigation by then-prosecutor general Viktor Shokin, who the U.S., United Kingdom and other Western governments argued had failed to rein in corruption in the country.

The U.S. threatened to withhold roughly $1 billion in loan guarantees if Shokin was not replaced as prosecutor general, a message Joe Biden delivered to officials in Kyiv while serving as vice president and recounted during a 2018 Council on Foreign Relations conference.

While many of Trump's allies and some former government officials have argued that there was minimally a conflict of interest in the case, the former vice president has denied acting with his son's business interests in mind. There is no evidence of any criminal wrongdoing by either of the Bidens and no evidence that Hunter Biden's work influenced U.S. policy.

The president has trailed Joe Biden in polls consistently for months, with the impeachment investigation and subsequent focus on Hunter Biden's business dealings failing to deliver a blow to the former vice president's candidacy.

The Trump campaign has telegraphed that it will make the allegations about Hunter Biden's work overseas a consistent part of its closing message, with time running out for Trump to turn the tide before Nov. 3.

"The contrast between a 47-year swamp creature in Joe Biden and a businessman in President Trump has been a major focus of this campaign, a major theme of this campaign and I would expect it to be so through Election Day," senior campaign adviser Jason Miller told reporters on Wednesday.

Miller suggested the campaign may even expand its focus to include how Biden's brothers James Biden and Frank Biden made their money, calling the Post report "the tip of the iceberg of the close look at the Biden family business."