(CNN) The House Ways and Means Committee received information from a federal employee at the end of July alleging that there was "possible misconduct" and "inappropriate efforts to influence" the Presidential audit program, according to a letter from the committee's chairman.

Committee Chairman Richard Neal is suing the US Treasury and the Internal Revenue Service to obtain six years of President Donald Trump tax returns as well as records from several of his business entities. The Presidential tax audit program, conducted by the IRS, automatically audits every incoming President's taxes and Neal has argued that he wants the records to make sure the Presidential tax audit program is working properly or if necessary make legislative fixes.

Trump and his defenders have argued there is no legislative purpose for the committee to have access to Trump's returns and that Neal, a Massachusetts Democrat, is only interested in getting information that could be damaging to the President.

Neal wrote to Treasury Secretary Steven Mnuchin about the complaint, and included a version of the letter in an August court document.

Neal said in his letter to Mnuchin that the allegation underscores the need for oversight of the program. The House has argued it needs the information to understand how the Presidential audit program, which is not enshrined in law and is shrouded in mystery, is carried out. Democrats argue that any allegation that the program was carried out differently under Trump could bolster the House's case.

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