The Federal Bureau of Investigation, accused of abusing its power in its probe of links between President Donald Trump's election campaign and Russia, has become a political punching bag, experts in the US law enforcement community say.
But after two years of becoming deeply enmeshed in the swirl of American politics -- at one point in 2016, it was investigating both Trump's team and Democratic rival Hillary Clinton -- the FBI also needs to clean up its image, they say.
"I think that there are troubling things that myself, many former agents, as well as current on-board employees, would like to see a full accounting of," said retired special agent James Gagliano.
In the past few years, actions by the agency's top management "have had a deleterious effect on the reputation of the FBI," Gagliano, who is now an adjunct assistant professor at St John's University in New York, told AFP.
The FBI was accused of both aiding Clinton's campaign and causing her loss.
Since then, Trump and his Republican Party claim that the agency has tried to discredit his victory -- and possibly help force him from office -- by opening a special investigation into possible collusion with Moscow.
The FBI took another brutal hit Friday when Trump spearheaded a Republican effort to tar the agency as deeply politicized, with the release of a secret, controversial GOP memo.
But the agency's director Christopher Wray -- who was hand-picked by Trump six months ago, but whose future now seems unclear -- has so far stood tall.
"Talk is cheap," he told his 35,000-strong staff after the memo release, in an internal letter obtained by AFP.
- History of clashes -
Trump's battle with the Justice Department and FBI is not new, and is just one in a long series of fights between presidents and their top law enforcement officials.
Legendary G-Man J. Edgar Hoover, the agency's first director who served for nearly a half-century, turned the FBI into an institution feared by crooks and politicians alike.
Presidents from Harry Truman to Richard Nixon considered dismissing him, but Hoover was seen as too powerful -- and dangerous.
The FBI director is appointed for a term of 10 years -- a method seen as ensuring he or she remains apolitical. But some critics say that goal has not been met.
The root of the current battle is former director James Comey's personal handling of the 2016 investigation into Clinton's use of an unauthorized personal email server while she was secretary of state.
His attempts to keep that sensitive probe apolitical fell flat, reaping attacks from both parties even as he twice found the evidence lacking to charge her.
"The Clinton investigation put the FBI in the center of the political battle," said Jeffrey Ringel, a veteran agent who is now director of the Soufan Group, a security consultancy.
"Either way, the FBI was going to come out bruised."
- The Russia probe -
After becoming president, Trump took umbrage when Comey pursued allegations that Russia had meddled in the 2016 election to help the real estate mogul win.
Comey refused to back off and declare loyalty to Trump, who fired him, accusing him of being pro-Democrat.
Since then, Trump has built a campaign against the agency, alleging that Comey, his onetime deputy Andrew McCabe, agents who served on both the Clinton and Trump probes, and some Justice Department officials were biased against him.
Republicans say leaked text messages show that two investigators working both cases were deeply anti-Trump. They note that McCabe's wife was supported by Clinton in a failed run for state office in Virginia.
Before Friday's release of the memo, Trump said leaders of both the FBI and the Department of Justice had "politicized the sacred investigative process in favor of Democrats and against Republicans - something which would have been unthinkable just a short time ago."
- Impossible situation -
FBI agents say Comey made the best of an impossible situation -- investigating two top candidates during an election.
But he also plunged the agency too much into the limelight, and blurred the lines of impartiality, they said.
Gagliano says while the agency's current predicament is not unprecedented, "it is unsettling."
He insisted that while agents have their political leanings, they rigorously put them aside on the job, and that only "a few people" had compromised that.
"Their impartiality, their lack of a political agenda has been compromised to some extent via a few people," he noted.
Most analysts have dismissed the criticisms in the so-called "Nunes memo" released by the House Intelligence Committee on Friday as deeply distorted and unfair to the FBI.
But current and former agents say Wray needs to strongly defend the agency -- while clearing the cloud of political bias hanging over the staff.
"Wray needs to stress among the rank and file that the FBI must be seen as apolitical and cannot let their personal opinions affect their investigative actions," Ringel said.