In a recent revelation, the IRS whistleblower involved in Hunter Biden's federal tax investigation has been identified as Joseph Ziegler, a 13-year veteran of the IRS. Ziegler, previously known as "Whistleblower X", came forward on Wednesday to testify before Congress, alleging that he felt restrained by the Department of Justice (DOJ) throughout the five-year probe.

Ziegler claimed that he was regularly obstructed by the DOJ, particularly when it came to pursuing leads that could have potentially implicated Hunter's father, President Joe Biden, in the investigation. He also stated that he had discovered evidence that supported "more serious charges" against Hunter than the misdemeanor charges the first son was slapped with last month.

"When you're prevented from going down certain roads, I guess I don't know what could have been found if we were not hamstrung or not handcuffed," Ziegler told CBS News.

Ziegler, along with IRS supervisor Gary Shapley, claimed that they had uncovered evidence that "supported felony and misdemeanor tax charges” against Hunter. However, their requests for felony charges were not approved. Their attempts to question other Biden family members were also denied, with fears that such interviews would "get [them] into hot water."

"In August of 2022, we had a phone call with all of the assigned prosecutors and they had said that all four of them were recommending the approval of felony and misdemeanor tax charges," Ziegler said. He questioned whether all taxpayers were being treated the same, expressing his belief that in this case, they were not.

Hunter Biden's attorney, Cristopher Clark, dismissed Ziegler’s claims as "preposterous and deeply irresponsible." Democratic House Rep. Jamie Raskin of Maryland also questioned Ziegler’s allegations, stating that he had not seen any evidence that Hunter "received any kind of official favoritism in this prosecution for being Joe Biden's son."

Ziegler alleged that Hunter had "improperly claimed" a number of business deductions for personal expenses, including his children’s college tuition, hotel bills, and alleged payments to escorts. He also claimed he was denied approval to gather location data to determine whether President Biden was in the room with Hunter when Hunter allegedly threatened a Chinese businessman in 2017.

"I do this with a heavy heart,” Ziegler said regarding his recent testimony. “This is awful. It's not a fun experience to go through this. I don't wish this upon anyone."