David C. Weiss, the federal prosecutor in Delaware who has led the legal investigation of Hunter Biden, on Monday rebutted a key aspect of testimony to Congress by an Internal Revenue Service official who mentioned that Mr. Weiss complained about being blocked from pursuing the case the way in which he wished.

In a letter to the Senate Judiciary Committee, Mr. Weiss mentioned that he had by no means requested Justice Department officers to present him particular counsel standing to pursue the case, contradicting testimony to the House Ways and Means Committee by the I.R.S. official, Gary Shapley, who mentioned Mr. Weiss had sought that standing and been turned down.

Mr. Weiss urged that Mr. Shapley might need misunderstood him throughout an October 2022 assembly. Mr. Weiss, the U.S. lawyer for Delaware, who was appointed to the function below President Donald J. Trump, mentioned within the letter that he had approached a division higher-up about the opportunity of requesting standing as a particular lawyer, not as a particular counsel.

Deputizing a federal prosecutor as a particular lawyer is distinct from making one a particular counsel. The particular lawyer provision is, in essence, a workaround that permits an outsider to intervene in instances that span a number of jurisdictions or have particular circumstances. The particular counsel rules, in contrast, include inner Justice Department reporting necessities and congressional oversight provisions.

“To clarify an apparent misperception and to avoid future confusion, I wish to make one point clear: In this case, I have not requested special counsel designation,” Mr. Weiss advised Senator Lindsey Graham of South Carolina, the highest Republican on the Senate Judiciary Committee.

Instead, Mr. Weiss mentioned he “had discussions with departmental officials regarding potential appointment” as a particular lawyer, “which would have allowed me to file charges in a district outside my own without the partnership of the local U.S. attorney.”

Mr. Weiss added within the letter to Mr. Graham that he had “never been denied the authority to bring charges in any jurisdiction.”

Mr. Weiss has sought to defend the integrity of the five-year investigation after a plea deal announced last month below which Mr. Biden will plead responsible to 2 misdemeanor tax costs and settle for phrases that will enable him to keep away from prosecution on a separate gun cost.

Republicans have assailed it as a “sweetheart deal” for the president’s son and have used Mr. Shapley’s testimony to advertise the concept that political interference performed a job within the final result. Speaker Kevin McCarthy has left open the opportunity of pursuing impeachment costs towards Attorney General Merrick B. Garland.

In Monday’s letter — a follow-up to a less detailed response he despatched to House Republicans in late June — Mr. Weiss backed up an earlier assertion by Mr. Garland that he had been given full authority within the case. At the identical time, Mr. Weiss acknowledged publicly for the primary time that he had thought of searching for a option to deliver doubtlessly extra critical tax costs towards Mr. Biden outdoors Delaware.

Mr. Weiss, who has described the Hunter Biden investigation as “ongoing,” didn’t say if he had adopted by way of and requested to be appointed particular lawyer to the profession official who served as his contact at Justice Department headquarters.

Nor did he explicitly tackle a key assertion made by Mr. Shapley: that Biden-appointed U.S. attorneys in California and Washington had blocked Mr. Weiss from prosecuting Hunter Biden on felony tax costs stemming from a interval when the president’s son was incomes thousands and thousands working with foreign-controlled companies and traders.

The investigation was initiated by the Trump Justice Department in 2018 and finally handed to Mr. Weiss, a Republican whose fame for nonpartisanship had earned him the help of Delaware’s two Democratic senators throughout his affirmation just a few months earlier.

After President Biden was elected, the division’s interim management stored Mr. Weiss in place and answerable for the inquiry. Mr. Garland, after being confirmed, continued that association and was wanting to keep away from any suggestion of political meddling.

Mr. Shapley, testifying earlier than the House Ways and Means Committee in May below what Republicans mentioned had been whistle-blower protections, mentioned he and different investigators had witnessed Mr. Weiss saying final yr that he wouldn’t be the “deciding official” relating to whether or not to prosecute Mr. Biden. Mr. Shapley mentioned that Mr. Weiss had been turned down when he sought particular counsel standing after being advised by native prosecutors that he couldn’t deliver costs. House Republicans launched the testimony final month.

Mr. Shapley recounted arguing in conferences with Mr. Weiss and different prosecutors to aggressively pursue costs towards Hunter Biden stemming from his failure to pay taxes in 2014 and 2015, two years not lined below Mr. Biden’s settlement to plead responsible on the misdemeanor tax costs. During these years, Mr. Biden was incomes revenue from work for a Ukraine-based vitality firm and Chinese purchasers that Mr. Shapley urged was being channeled by way of entities that had a presence in Washington and the Los Angeles space.

In mid-2022, Mr. Weiss reached out to the highest federal prosecutor in Washington, Matthew Graves, to ask his workplace to pursue costs and was rebuffed, in accordance with Mr. Shapley’s testimony. The same request to prosecutors within the Central District of California, which incorporates Los Angeles, was additionally rejected, Mr. Shapley testified.

A second former I.R.S. official, who has not been recognized, advised House Republicans the identical story. That episode was confirmed independently to The New York Times by an individual with data of the state of affairs.

Mr. Shapley, who oversaw the company’s function within the investigation of Mr. Biden’s taxes, additionally advised House committee aides that his criticism of the Justice Department led to him being denied a promotion. In his testimony, he blamed Mr. Weiss for criticizing him to his superiors.

Mr. Weiss denied that cost in a June 30 letter to Representative Jim Jordan, Republican of Ohio and the chairman of the House Judiciary Committee, saying that he “did not retaliate” towards Mr. Shapley.