New York — A government whistleblower is alleging "inappropriate efforts to influence" the mandatory IRS audit program that's checking the tax returns of President Trump and Vice President Pence.

The chairman of the House Ways & Means Committee, Representative Richard Neal, D-Mass., says the panel on July 29 received "an unsolicited communication from a Federal employee setting forth credible allegations of 'evidence of possible misconduct' - specifically, potential 'inappropriate efforts to influence' the mandatory audit program."

Massachusetts Democratic Representative Richard Neal in November 2017 Win McNamee / Getty Images

Citing "multiple people familiar with the document," The Washington Post says, "An Internal Revenue Service ­official has filed a whistleblower complaint reporting that he was told that at least one Treasury Department political appointee attempted to improperly interfere with the annual audit of the president's or vice president's tax returns."

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The Post adds that, "Trump administration officials dismissed the whistleblower's complaint as flimsy because it is based on conversations with other government officials."

In an Aug. 8 letter to Treasury Secretary Steven Mnuchin, Neal sought documents and communications regarding specific employees at the department and the Internal Revenue Service. In a court filing, it was disclosed that Mnuchin missed the deadline to begin producing the documents.

Internal IRS policies require annual audits of presidential and vice presidential tax returns, but the policies aren't law.

The Post notes that the audits are supposed to be shielded from politics and political appointees.

The whistleblower claim comes amid the House's impeachment inquiry into Mr. Trump in the wake of a different government whistleblower's complaint about the president's actions toward Ukraine.

Mr. Trump's tax returns have been a well-kept secret. He broke with U.S. political tradition as the first president in decades not to give voters a look at his financial situation. Democrats sued for their release.

Separately, Manhattan's top prosecutor pushed back against the U.S. Justice Department Thursday in a legal battle over Mr. Trump's tax returns, saying local efforts to investigate the president's finances should be "free from federal interference."

A day after federal prosecutors asked for a delay, District Attorney Cyrus R. Vance Jr. filed court papers saying the Justice Department is supporting Mr. Trump's efforts to run out the clock on certain statutes of limitation that could affect a state grand jury investigation.

Vance and Mr. Trump have been fighting over a subpoena issued this summer for the president's tax returns as part of a criminal inquiry into the hush-money payments made to two women who claimed to have had affairs with the president.

The grand jury also subpoenaed the Trump Organization for records related to payments that former Mr. Trump lawyer Michael Cohen helped arrange to the porn actress Stormy Daniels and model Karen McDougal during the 2016 presidential campaign.

Mr. Trump has denied any sexual relationship with either woman and said any payments were personal matters, not campaign expenses.

The Justice Department on Wednesday asked a judge to temporarily delay enforcement of the subpoena for Mr. Trump's tax returns so the court can consider the president's argument that he can't be investigated while in office.

The Republican president has said Vance's investigation is unconstitutional and part of an effort by elected Democrats to harass him.

Attorneys for Vance counter that Mr. Trump's immunity shouldn't interrupt a probe that includes the actions of individuals and businesses other than Mr. Trump.

"Also of concern is the State's sovereign right to enforce its criminal laws free from federal interference," they wrote in a court filing Thursday.

They added that it was "audacious" for the Justice Department to seek a delay, considering they conducted a similar investigation last year "into some of the very same transactions and actors."

That investigation resulted in Cohen pleading guilty to federal charges that the hush-money payments amounted to illegal campaign contributions. Federal prosecutors didn't charge Mr. Trump or anyone else involved in either arranging the payoffs or reimbursing Cohen through Mr. Trump's company.

The Justice Department and U.S. attorney's office in Manhattan declined to comment on Vance's filing.