The federal prosecutor appointed by Attorney General William P. Barr to review whether Obama-era officials improperly requested the identities of individuals whose names were redacted in intelligence documents has completed his work without finding any substantive wrongdoing, according to people familiar with the matter.

The revelation that U.S. Attorney John Bash, who left the department last week, had concluded his review without criminal charges or any public report will rankle President Trump at a moment when he is particularly upset at the Justice Department. The department has so far declined to release the results of Bash’s work, though people familiar with his findings say they would likely disappoint conservatives who have tried to paint the “unmasking” of names — a common practice in government to help understand classified documents — as a political conspiracy.

The president in recent days has pressed federal law enforcement to move against his political adversaries and complained that a different prosecutor tapped by Barr to investigate the FBI’s 2016 investigation of his campaign will not be issuing any public findings before the election.

Legal analysts feared that Bash’s review was yet another attempt by Trump’s Justice Department to target political opponents of the president. Even if it ultimately produced no results of consequence, legal analysts said, it allowed Trump and other conservatives to say Obama-era officials were under scrutiny, as long as the case stayed active.

The department — both under Barr and Trump’s previous attorney general, Jeff Sessions — has repeatedly turned to U.S. attorneys across the country to investigate matters of Republican concern, distressing current and former Justice Department officials, who fear that department leaders are repeatedly caving to Trump’s pressure to benefit his allies and target those he perceives as political enemies.

Kerri Kupec, the Justice Department’s top spokeswoman, had first revealed Bash’s review in May, after Republican senators made public a declassified list of U.S. officials, including former vice president Joe Biden, who made requests that would ultimately reveal the name of Trump adviser Michael Flynn in intelligence documents in late 2016 and early 2017.

In an appearance on Fox News that month, Kupec told host Sean Hannity that Barr had tapped Bash, the top federal prosecutor in San Antonio, to review Obama-era officials’ unmasking requests. She said that though the practice “inherently isn’t wrong,” the frequency with which requests were made or the motive for making them could be “problematic.”

Though “unmasking” is common and appropriate because it allows government officials to better understand a document they are reading, Trump and others suggested the list of requests that ultimately revealed Flynn’s name showed wrongdoing.

Bash’s team was focused not just on unmasking, but also on whether Obama-era officials provided information to reporters, according to people familiar with the probe, who spoke on the condition of anonymity to discuss a sensitive investigation. But the findings ultimately turned over to Barr fell short of what Trump and others might have hoped, and the attorney general’s office elected not to release them publicly, the people familiar with the matter said. The Washington Post was unable to review the full results of what Bash found.

Bash announced last week that he was leaving the department — surprising many in the Justice Department because the move came so close to the election — though he made no mention of the unmasking review. He said in a statement that he had informed the attorney general of the decision a month earlier and had “accepted an offer for a position in the private sector.” He gave formal resignation letters to the president and the attorney general on Oct. 5, and his last day was Friday.

Before being nominated as the U.S. attorney, Bash worked in the Solicitor General’s Office and as an associate counsel to the president. Bash thanked Trump and others in the statement, and Barr offered his “gratitude” for Bash’s service.

“I appreciate his service to our nation and to the Justice Department, and I wish him the very best,” Barr said.

Asked Tuesday if Bash had quit over anything related to unmasking, Kupec said, “No, that was not my understanding.” At the time Bash’s departure was announced, she had said of the unmasking review, “Without commenting on any specific investigation, any matters that John Bash was overseeing will be assumed by Gregg Sofer,” who was tapped to replace Bash as the U.S. attorney. She declined this week to comment specifically on the status of the unmasking investigation.

Bash declined to comment. A spokesman for the U.S. attorney’s office in San Antonio said he could not immediately comment.

It was not immediately clear why the department was holding back Bash’s findings. Officials do not generally discuss investigations that have been closed without criminal charges — though Bash’s case is unusual because it was announced publicly by the department spokeswoman. Justice Department policies and tradition, too, call for prosecutors not to take public steps in cases close to an election that might affect the results.

Before Bash’s appointment, Kupec had said that a different federal prosecutor, John Durham in Connecticut, also had been looking at unmasking as part of his broader investigation into the FBI’s 2016 probe of whether the Trump campaign coordinated with Russia to influence the election. It was not clear how Durham’s and Bash’s work intersected.

Barr recently told some Republican lawmakers that no report of Durham’s investigation would be released before the November election, though unlike Bash’s review, Durham’s work seems to be ongoing, people familiar with the matter said. Trump has in recent days called the delay in the Durham case “a disgrace,” and asserted that his 2016 Democratic opponent, Hillary Clinton, should be jailed. He was previously critical of another prosecutor specially tapped by then-Attorney General Sessions to investigate matters related to Clinton, but whose case ended with no public report or allegations of wrongdoing.

Barr had said previously he would not hold back Durham’s findings because of concerns about any impact on the election, as investigators were not focused on political candidates.

From early on in the Trump administration, some GOP lawmakers have sought to investigate and highlight Obama-era unmasking requests, believing them to be inappropriate. The effort was initially pushed in part by Rep. Devin Nunes (R-Calif.), though the House Intelligence Committee he chaired at the time also asked U.S. spy agencies to reveal the names of U.S. individuals or organizations contained in classified intelligence on Russia’s interference in the 2016 presidential election.

In May, Republican Sens. Ron Johnson (Wis.), Charles E. Grassley (Iowa) and Rand Paul (Ky.) breathed new life into the effort, releasing a list of those who had made unmasking requests. The list included the names of more than three dozen former Obama administration officials. Among them were Biden, former White House chief of staff Denis McDonough, former FBI director James B. Comey, former CIA director John Brennan and former director of national intelligence James R. Clapper Jr.

Then-acting director of national intelligence Richard Grenell had declassified and personally delivered the list to the Justice Department — his arrival captured by a pre-positioned Fox News camera — on the same day the Justice Department moved to drop criminal charges against Flynn.

Paul said at the time that “we sort of have the smoking gun because we now have the declassified document with Joe Biden’s name on it.” And Trump renewed his broader attacks on the investigation of possible coordination between Russia and his campaign, suggesting those involved should be jailed.

“I’m talking with 50-year sentences,” Trump said in an interview with Fox Business Network.

Kupec soon appeared on Fox News and announced Bash’s inquiry. His work came on top of that of Durham and U.S. Attorney Jeff Jensen in St. Louis, who had been tapped specially to review the Flynn case and ultimately advised that the Justice Department should drop it.

The end of Bash’s case is similar to that of a review conducted by John Huber, the U.S. attorney in Utah, who was asked in November 2017 by Sessions to look into concerns raised by Trump and his allies in Congress that the FBI had not fully pursued cases of possible corruption at the Clinton Foundation and during Clinton’s time as secretary of state. The Post reported in January that the inquiry had effectively ended with no tangible results. In the months that followed, Trump bemoaned the state of the inquiry on Twitter, asserting that Huber “did absolutely NOTHING.”

“He was a garbage disposal unit for important documents & then, tap, tap, tap, just drag it along & run out of time,” Trump wrote.