It's been 10 months since Washington learned that former British spy Christopher Steele, author of the so-called "Trump dossier," took the Hillary Clinton-funded opposition research document to the FBI, which considered sponsoring the anti-Trump work at the height of the 2016 presidential campaign. Now, congressional investigators have made what is perhaps an even more consequential discovery: Knowledge of the dossier project, during the campaign, extended into the highest levels of the Obama Justice Department.

The department's Bruce Ohr, a career official, served as associate deputy attorney general at the time of the campaign. That placed him just below the deputy attorney general, Sally Yates, who ran the day-to-day operations of the department. In 2016, Ohr's office was just steps away from Yates, who was later fired for defying President Trump's initial travel ban executive order and still later became a prominent anti-Trump voice upon leaving the Justice Department.

Unbeknownst to investigators until recently, Ohr knew Steele and had repeated contacts with Steele when Steele was working on the dossier. Ohr also met after the election with Glenn Simpson, head of Fusion GPS, the opposition research company that was paid by the Clinton campaign to compile the dossier.

Word that Ohr met with Steele and Simpson, first reported by Fox News' James Rosen and Jake Gibson, was news to some current officials in the Justice Department. Shortly after learning it, they demoted Ohr, taking away his associate deputy attorney general title and moving him full time to another position running the department's organized crime drug enforcement task forces.

The news also stunned some of those who had been investigating the matter. Yes, they knew that knowledge of the dossier extended to some officials in the FBI. That was bad enough; how could the FBI endorse and consider underwriting one campaign's dirt-digging operation in the middle of a hotly contested election? But now investigators know that nearly the highest levels of the Obama Justice Department were also aware of the dossier.

Related: Why the FBI director walked a tightrope on the Steele dossier

Investigators believe the dossier's sensational allegations of collusion between Russia and the Trump campaign played a role in the beginning of the FBI's counterintelligence investigation into the Trump-Russia affair — an investigation that later morphed into special counsel Robert Mueller's probe.

House Intelligence Committee Chairman Devin Nunes, R-Calif., whose investigation has led to a number of revelations about the dossier, was unhappy to learn about such a key piece of information months after the investigation began. Ohr's contacts with Steele and Simpson were covered by a subpoena Nunes issued to the FBI and the Justice Department on Aug. 24. Yet as recently as Tuesday, when Nunes, along with House Oversight Committee Chairman Trey Gowdy, R-S.C., met with deputy attorney general Rod Rosenstein, the department said nothing about Ohr's role.

"Pursuant to the House Intelligence Committee's prior subpoenas and information requests, the Department of Justice should have provided the committee with information on contacts that DOJ official Bruce Ohr had with Fusion GPS representatives and Christopher Steele," Nunes said in a statement Thursday. "The committee will issue a subpoena to Bruce Ohr for information on this matter."

The Ohr revelation comes not long after word that top FBI agent Peter Strzok was removed from the Mueller investigation for anti-Trump text messages he exchanged with a top FBI lawyer who had also worked for the Mueller probe. Now, with news of Ohr's contacts with Steele and Simpson, Republicans on Capitol Hill — and perhaps some Democrats, too — will wonder just how far the Obama Justice Department officials went in the effort to stop Trump.

Also read: Byron York: In Trump-Russia probe, was it all about the Logan Act?