An IRS special agent said to be involved in the federal investigation into Hunter Biden’s taxes is seeking whistleblower protections to provide sensitive disclosures about the probe to Congress.

Mark D. Lytle, a lawyer for the unnamed IRS employee, wrote in a letter Wednesday to a bipartisan group of lawmakers that he represents a “career IRS Criminal Supervisory Special Agent who has been overseeing the ongoing and sensitive investigation of a high profile, controversial subject since early 2020” and would like to make protected whistleblower disclosures to Congress.

While Lytle did not name Biden in the letter, which was obtained by NBC News, a source familiar with the matter who also verified its authenticity said the investigation refers to the federal probe into the finances of President Joe Biden’s son Hunter.

The letter was previously reported by CBS News and The Wall Street Journal.

According to Lytle, the IRS special agent is prepared to provide information that would “contradict sworn testimony to Congress by a senior political appointee,” reveal failures to handle “clear conflicts of interest” in the case and detail instances of “preferential treatment and politics improperly infecting decisions and protocols.”

Lytle went on to say his client has notified the offices of inspector general at both the Treasury Department, which oversees the IRS, and the Justice Department through “legally protected disclosures.”

The Treasury Department and Lytle did not immediately respond to requests for comment. The Justice Department and the IRS declined to comment.

Lytle proposed meeting with lawmakers to determine a way forward, saying his client had held back on sharing certain details, making it “challenging for me to make fully informed judgments about how best to proceed.”

House Oversight Committee chair James Comer, whose panel is investigating Biden family finances, called the allegations in Lytle’s letter “concerning.”

“It’s deeply concerning that the Biden Administration may be obstructing justice by blocking efforts to charge Hunter Biden for tax violations,” Comer, R-Ky., said in a statement. “We’ve been wondering all along where the heck the DOJ and the IRS have been. Now it appears the Biden Administration may have been working overtime to prevent the Bidens from facing any consequences.”

Comer was not one of the nine recipients of Lytle’s letter, which was sent to the top Democrat and Republican on the House and Senate Judiciary and tax-writing committees. It was also sent to Sen. Chuck Grassley, R-Iowa, a co-chair of the Whistleblower Protection Caucus.

House Ways and Means Committee chair Jason Smith, R-Mo., said in a statement that his panel looks forward “to sitting down promptly with this individual to better understand the scope and detail of the concerns raised. The Committee takes seriously any allegations of misconduct by government officials or offices and will, on behalf of American taxpayers, look into concerns that are brought to our attention.”

NBC News did not immediately receive a response from the other committees or Grassley.