The Hunter Biden tax investigation — codenamed "Sportsman" — was opened in November 2018 as an "offshoot" of an IRS investigation into a "foreign-based amateur online pornography platform," a whistleblower told the Houses Ways and Means Committee.

The committee on Thursday released testimony from two IRS whistleblowers who said officials at the Justice Department, FBI and IRS interfered in the investigation into Hunter Biden. The whistleblowers said decisions in the case seemed to be "influenced by politics."

One whistleblower, Gary Shapley Jr., who was the supervisor of the investigation at the IRS, said that decisions "at every stage" of the probe were made that "had the effect of benefiting the subject of the investigation."

Shapley detailed the origins of the probe in congressional testimony unsealed Thursday.

DOJ, FBI, IRS INTERFERED WITH HUNTER BIDEN PROBE, ACCORDING TO WHISTLEBLOWER TESTIMONY RELEASED BY GOP

Hunter Biden Air Force One

Whistleblower testimony on the Hunter Biden tax investigation was released by the House Ways and Means Committee on Thursday. (Reuters/Elizabeth Frantz/File)

"The investigation into Hunter Biden, code name ‘Sportsman,’ was first opened in November 2018 as an offshoot of an investigation the IRS was conducting into a foreign-based amateur online pornography platform," Shapely testified. Testimony released by the committee didn't include any further explanation of how the pornography outlet and Biden were linked.

The investigation had previously been believed to have been predicated, in part, by suspicious foreign transactions.

Nearly a year later, in October 2019, Shapley said the "FBI became aware that a repair shop had a laptop allegedly belonging to Hunter Biden and that the laptop might contain evidence of a crime."

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"The FBI verified its authenticity in November of 2019 by matching the device number against Hunter Biden's Apple iCloud ID," Shapley said. "When the FBI took possession of the device in December 2019, they notified the IRS that it likely contained evidence of tax crimes."

Joe Biden waving with Hunter Biden

One whistleblower said the investigation into Hunter Biden, right, was related to a probe of a foreign pornography operation. (Nicholas Kamm/AFP via Getty Images/File)

The laptop repair shop owner, John Paul Mac Isaac, was subpoenaed to testify before the U.S. District Court in Delaware in December 2019.

HUNTER BIDEN AGREES TO PLEAD GUILTY TO FEDERAL TAX CHARGES

The FBI's property receipt for the laptop, first obtained by Fox News Digital in 2020, had a "Case ID" section, which was filled in with a handwritten number: 272D-BA-3065729.

The number "272" is the FBI's classification for money laundering, while "272D" refers to "Money Laundering, Unknown SUA [Specified Unlawful Activity]—White Collar Crime Program," according to FBI documents. One government official described "272D" as "transnational or blanket."

Shapley said the FBI verified the authenticity of the laptop, even though many Biden allies said it was Russian disinformation.

Hunter Biden in Ireland

Hunter Biden. (Brian Lawless/PA Images via Getty Images/File)

The revelations come just days after the Justice Department announced that Hunter Biden will plead guilty to two misdemeanor counts of willful failure to pay federal income tax as part of a deal that is expected to keep him out of prison. The president's son also agreed to enter into a pretrial diversion agreement with regard to a separate charge of possession of a firearm by a person who is an unlawful user of or addicted to a controlled substance.

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In response to the whistleblower allegations, the Justice Department said in a statement: "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. He needs no further approval to do so. Questions about his investigation should be directed to the U.S. Attorney’s Office for Delaware."