IRS whistleblowers are expected to testify at the House Oversight Committee Wednesday that they witnessed an “undeniable pattern of preferential treatment” for the Bidens, and “obstruction of the normal investigative process” throughout the years-long federal investigation into Hunter Biden.

IRS whistleblower Gary Shapley, who served as the supervisor on the investigation at the IRS, and a second anonymous whistleblower bringing similar accusations, will offer testimony to the House Oversight Committee starting at 1 p.m.

The anonymous whistleblower, who previously testified before the House Ways & Means Committee last month, is expected to reveal his identity as a 13 year-special agent within the IRS’ Criminal Investigation Division and as a “gay Democrat married to a man,” according to his prepared testimony obtained by Fox News Digital.

The whistleblowers have alleged officials at the Justice Department, FBI and IRS interfered in the investigation into Hunter Biden and said decisions in the case seemed to be “influenced by politics.”

They also alleged federal prosecutors blocked lines of questioning related to President Biden and said the U.S. attorney in charge of the probe, David Weiss, did not have full authority to bring charges.

The anonymous whistleblower, according to his prepared testimony, will say that Hunter Biden “should have been charged with a tax felony, and not only the tax misdemeanor charge,” and that communications and text messages reviewed by investigators “may be a contradiction to what President Biden was saying about not being involved in Hunter’s oversea business dealings.”

That whistleblower is also expected to testify on several instances in which prosecutors “did not follow the ordinary process, slow-walked the investigation, and put in place unnecessary approvals and roadblocks from effectively and efficiently investigating the case,” including prosecutors blocking questioning and interviewing of Hunter Biden’s adult children.

The whistleblower is also expected to ask Congress and the Biden Administration to “consider a special counsel” for the Hunter Biden investigation and “all the related cases and spin-off investigations that have come forward from this investigation.”

“Related cases that I believe are subject to the same problems and difficulties we had,” the whistleblower is expected to say, and expected to add that Congress should consider “establishing an official channel for Federal investigators to pull the emergency cord and raise the issue of the appointment of a special counsel for consideration by your senior officials.”

It is unclear, at this point, to which “related cases and spin-off investigations” the whistleblower is referring.