WASHINGTON A career IRS employee told lawmakers that officials in the U.S. Department of Justice slow-walked investigations and stifled some tax charges against President Joe Bidens son.

A supervisory special agent with the IRS Criminal Investigation division named Gary Shapley said an inquiry into Hunter Bidens taxes has been hampered by the Justice Department at every turn.

Shapley made the allegation during a transcribed interview with the House Ways and Means Committee in May, however weeks before a federal prosecutor charged the younger Biden with misdemeanors for failing to pay federal taxes in 2017 and 2018.

Nevertheless, Republicans said Shapleys testimony revealed scandalous favoritism for the presidents son, further vindicating GOP claims of a two tier justice system biased against Republicans and former President Donald Trump.

We have credible whistleblower testimony alleging misconduct and government abuse that is resulting in preferential treatment for the presidents son, Hunter Biden, Ways and Means chair Jason Smith (R-Mo.) said Thursday. The federal government is not treating taxpayers equally when enforcing tax laws.

Rep. Darin LaHood (R-Ill.), a member of the committee, said it wasnt a coincidence that the Justice Department charged Hunter Biden shortly before the testimony became public.

This could have been done a long time ago it wasnt, so I want people to pay close attention to the timing of the plea agreement and what happened here today, LaHood said. Why was it done so abruptly and quickly?

The committee voted Thursday to make Shapleys testimony public, as well as testimony from another whistleblower who remains anonymous but said he worked with Shapley and shared essentially the same story. Its illegal to disclose private tax information, but theres an exception in the law for Ways and Means and the other congressional committees overseeing tax law. Shapley first spoke out in an interview with CBSNews last month ; the committee interview contains detailed information about several years of Hunter Bidens taxes.

Shapleys testimony described an apparent bureaucratic turf war between his team at the IRS and the Justice Department over the Biden case, with career DOJ officials dragging their feet on approving investigative steps, such as search warrants that Shapley thought were necessary.

One of Shapleys key allegations is that his team thought the government should pursue charges against Biden in Washington, D.C., and California for failing to pay taxes on payments he received over several years, but that the Justice Department wouldnt allow it.

In an October meeting with Delaware U.S. Attorney David Weiss, a Trump appointee whom the president left in his position so as not to appear to be influencing the investigation of his son, Weiss allegedly said he couldnt bring charges in Washington.

As Shapley recalled, He surprised us by telling us on the charges: Im not the deciding official on whether charges are filed. He then shocked us with the earth-shattering news that the Biden-appointed D.C. U.S. Attorney Matthew Graves would not allow him to charge in his district.

Weiss saying he lacked authority to charge Biden outside of Delaware would contradict statements by U.S. Attorney General Merrick Garland, who has said Weiss had a free hand to bring cases in any state, and Weiss himself, who said in a letter to House Republicans earlier this month that he had been granted ultimate authority over this matter, including responsibility for deciding where, when and whether to file charges.

A spokesperson for the Justice Department denied Weiss had been restricted.

As both the attorney general and U.S. Attorney David Weiss have said, U.S. Attorney Weiss has full authority over this matter, including responsibility for deciding where, when, and whether to file charges as he deems appropriate, the spokesman said. He needs no further approval to do so.

Weisss office declined to comment. A spokesperson for Graves said Weiss did not need approval from this office or the U.S. attorney to bring charges in the District of Columbia.

The charges Weiss brought against Biden were filed in Delaware . Biden agreed to plead guilty to the tax charges and to enter pretrial diversion to forestall a felony gun charge.

Shapley said the October meeting with Weiss was a red line moment, the turning point when he knew he would blow the whistle, though he indicated in his testimony that hed been keeping a record of seemingly unusual behavior by the Justice Department all along. As soon as he complained to superiors about the handling of the Biden investigation, he said they retaliated by removing him from the case and passing him over for a promotion for which I was clearly most qualified.

Rep. Richard Neal (D-Mass.), the top Democrat on Ways and Means, said that Shapleys retaliation claims are under investigation by IRS agency watchdogs and that Republicans jumped the gun in publicizing Hunter Bidens private tax information. He said the fact that the other whistleblower is anonymous is a red flag, as well as the fact that the anonymous whistleblower recently recanted a small part of his testimony in a letter to the committee .

Lets get the facts straight: This tax case is being handled by the Department of Justice and the Trump-appointed U.S. attorney for the District of Delaware, Neal said. We must allow these law enforcement agencies to complete their work.