(CNN) Bruce Ohr, the career Justice Department official targeted by President Donald Trump as a "creep" and a "disgrace," is facing a grilling by Republican lawmakers Tuesday on Capitol Hill.

The closed-door session is expected to focus on Ohr's relationship with Christopher Steele, the British spy behind the dossier that included salacious and unverified intelligence on Trump and Russia. It is an unlikely turn in the spotlight for the nearly 30-year veteran of the Department of Justice, who has built a reputation as the "consummate government servant" and an expert on global organized crime.

Since the House is on recess, Democratic members of Congress are absent from the hearing. Instead, the staff of the Democrats who sit on the House Judiciary and Oversight Committees are expected to attend the closed-door hearing, according to minority committee staffers.

A handful of committee Republicans members, including Reps. Trey Gowdy, Mark Meadows and Jim Jordan, are at the hearing and participating in questioning. It is the latest in a series of interviews conducted by the committees, who have been probing the controversial FBI investigations into 2016 candidates for nearly a year.

Little is known publicly about the extent of the relationship between Ohr and Steele, but some House Republicans who are vocal critics of the Russia investigation have seized on it as proof of an untoward connection between government officials and the roots of special counsel Robert Mueller's investigation.

Outside the ongoing hearing Tuesday, Meadows, a Trump ally and leading skeptic of the Russia investigation, told reporters that the FBI knew that the dossier was "unverified" and had "real credibility issues," likely before the law enforcement agency first used it as part of their evidence in requesting surveillance of Trump campaign associate Carter Page.

Speaking on a break in the closed-door hearing, which is expected to last for hours, Republican lawmakers said Ohr mishandled the information he was learning from outside government sources through his internal channels.

"Bruce Ohr handled evidence differently in this case than at any other point. I know of no circumstance where a lawyer would handle evidence the way that Bruce Ohr handled evidence in this case," Rep. Matt Gaetz, R-Fla., said.

Lawmakers also said Ohr was being forthright in his answers and had not been excessively conferring with his Justice Department and personal attorneys. Ohr has not, as of Tuesday morning, claimed spousal privileges as he answered the committees' questions, they said.

Gaetz said Ohr's testimony Tuesday had also revealed conflicts in previous testimony given by officials involved in the origins of the Russia investigation, including Glenn Simpson, the founder of Fusion GPS, and Lisa Page, a former FBI attorney, and called for them to appear at public hearings.

Earlier this month, Trump said he was considering stripping Ohr's security clearance "very quickly," a move that would likely render Ohr's current work as a senior counsel in the DOJ's Office of International Affairs difficult.

Ohr led the Justice Department's organized crime and racketeering section for over a decade, and through last year he served in a senior position within the deputy attorney general's Office until he was demoted, CNN reported, after messages were discovered between Steele and him, and the founder of the US firm that employed Steele, Fusion GPS.

Republicans have pointed to messages between Ohr and Steele turned over to Congress and recently reported in conservative outlets like The Washington Examiner and Fox News, suggesting the messages imply that Steele was using Ohr to maintain a relationship with the FBI after the bureau ended its relationship with him as a confidential source in the weeks before the 2016 election.

Lawmakers also said Ohr had provided the FBI with a copy of the dossier he had been given by Steele, but that it was after the FBI had already begun investigating some of Steele's reporting.

On Tuesday, Meadows would not confirm when Ohr handed over the elements of the dossier he'd received from Steele to the FBI, and did not divulge the source of Ohr's knowledge that he testified to about the FBI's early opinion of the dossier.

Meadows said he has learned whom within the FBI Ohr was in communication with but he would not share the information.

According to a letter from Senate Judiciary Chairman Chuck Grassley, the FBI interviewed Ohr 12 times between November 2016 and May 2017 about interactions with Steele.

The New York Times reported Monday that Ohr's recent contacts with Steele were part of a broader effort to determine whether the dossier's allegations were true. The FBI did not have all the reports Steele had provided and sought to obtain them, according to the Times.

"He's central to the universe of Christopher Steele and the Clinton-DNC-funded dossier and the investigation and targeting of President Trump," said Tom Fitton, the president of Judicial Watch, a conservative watchdog group that has sued to obtain government documents about Ohr.

Ohr's relationship with Steele has roots far beyond Steele's work for Fusion GPS into Trump. Ohr first came into contact with Steele in the mid-2000s, people who know him said, as both fought against the evolving threat of Russian organized crime for their respective countries.

At the time, Russian syndicates were supplanting elements of the Italian mafia and drug cartels as a key target of US law enforcement.

Former FBI Assistant Director Chris Swecker, who partnered with Ohr on Russian transnational crime cases in the early 2000s, called him a "very personable, very hardworking and very collaborative DOJ attorney."

"We appreciated him because of that collaborative part. Sometimes DOJ attorneys look at FBI agents as sort of the knuckle-draggers, like, 'We're the smart guys, just do what we tell you.' He was not that kind of guy," Swecker said.

As a section chief, Ohr traveled extensively as he built relationships with foreign partners, but mostly stayed out of the courtroom -- and the limelight.

Mark Matthews, an attorney who worked with Ohr at the Manhattan US attorney's office in the 1990s and maintained a relationship with him later in Washington, described him as a "very decent" and "classic public servant" who excelled at his supervisory role.

"Bruce was known in Washington for managerial skills. He was a guy who got along, without that ego," Matthews said.

Ohr's name first started appearing in the media last year as lawmakers investigated the origins of the dossier, and he has been amplified in recent weeks in tweets by the President, who has criticized him and his wife.

Simpson disclosed in a court filing last year that Ohr's wife, Nellie, worked for Fusion on "research and analysis of Mr. Trump" and that Simpson met with Bruce Ohr "at his request, after the November 2016 election to discuss our findings regarding Russia and the election."

Nellie Ohr, an academic and Russia expert, relied on open source documents to pull together information on Russian oligarchs as part of her employment with Fusion GPS, according to a person with knowledge of her work for the firm.

Neither Bruce nor Nellie Ohr has remarked publicly about the President. Ohr's attorney, Joshua Berman, declined to comment.

Ohr interviewed behind closed doors with the Senate Intelligence Committee in December. He was scheduled to appear before the House Intelligence Committee in January, but lawmakers canceled that meeting, according to a person familiar with the committee investigation.