(CNN) -- The inspector general for the intelligence community was unwilling to share details of the controversial whistleblower complaint, which is at the center of a dispute between the director of national intelligence and Congress, while answering questions behind closed doors in an intelligence committee hearing on Thursday, according to lawmakers present.
Inspector General Michael Atkinson told the committee that he was not allowed to provide details related to the substance of the complaint nor say whether the White House was involved in denying its release to Congress, because he was not authorized to do so, said Adam Schiff, chairman of the House Intelligence Committee, when speaking to reporters after the briefing.
CNN reported Thursday that the White House was involved, advising the nation's top intelligence agency that the controversial complaint is outside intelligence activities covered by laws governing intelligence whistleblowers, according to three sources familiar with the matter.
Atkinson would only discuss the process for his handling of the whistleblower's concerns, Schiff said. Lawmakers pressed for details nonetheless, though their efforts ultimately went unanswered.
That process was sharply criticized by Democrats, including Schiff, who said that his committee may take legal action if the complaint isn't turned over to Congress.
Rep. Mike Quigley, a Democrat on the committee, attacked the Justice Department and Attorney General Bill Barr for their involvement .
"In their mind it's to protect the President. And it doesn't matter if that violates the laws," he said.
Asked if lawmakers were told the Justice Department intervened in the process, Quigley answered: "The Department of Justice Opinions."
Quigley also added that "there's a lot more we have to learn."
The briefing was described in advance by Schiff as focusing on the "handling" of the complaint.
The Senate Intelligence Committee will also be briefed by Atkinson and acting Director of National Intelligence Joseph Maguire behind closed doors next week, a spokesperson told CNN Thursday, noting an exact date has not yet been selected.
Senate intelligence committee chairman, Republican Sen. Richard Burr and vice chairman Sen. Mark Warner, have been has been working with both officials and Warner has been significantly less outspoken about the complaint than Schiff, but the Senate spokesperson told CNN that the two men have been engaged in a bipartisan effort to ensure the situation is resolved and that the whistleblower's rights are protected, adding these cases should not be negotiated in the press.
The inspector general does not have the authority to discuss the details of the complaint with Congress because Maguire has not shared the actual report with the committee and has apparently not otherwise authorized Atkinson to share those details.
The intelligence whistleblower act does not allow for details to be provided until the actual complaint has been given to Congress, CNN legal contributor Steve Vladeck explained.
Democrats contend the DNI is violating the law, something the office disputes.
A source familiar with Tuesday's briefing told CNN that the inspector general indicated to lawmakers that he did not agree with the administration's assertion that details in the whistleblower complaint should be withheld from Congress.
Atkinson explained that he could not disclose the details in the complaint as the Justice Department stated it was outside the jurisdiction of DNI and therefore outside of the jurisdiction of the inspector general, the source said.
He also explained that "privileges" were being asserted by the administration, leaving lawmakers with the impression that the White House was directly involved in blocking the information from being turned over to Congress.
After Tuesday's briefing, the House Intelligence Committee released a new letter from Atkinson, dated September 17, saying he had determined he and the acting Director of National Intelligence Joseph Maguire were at an impasse over the issue of whether a whistleblower could contact Congressional lawmakers directly with "appropriate security practices."
That letter was sent Schiff and Ranking Minority Devin Nunes.
A communication between President Donald Trump and a foreign leader prompted the whistleblower complaint, a source familiar with the case told CNN.
The concern was first revealed by The Washington Post, which reported that an official in the American intelligence community was so bothered by a "promise" Trump made to a foreign leader that the official filed a formal whistleblower complaint with the inspector general of the intelligence community, citing two former US officials familiar with the matter. CNN has not independently confirmed the detail about a "promise" made to the foreign leader.
The source who spoke to CNN would not disclose the foreign leader with whom Trump was alleged to have spoken.
The Office of the Director of National Intelligence declined to comment. The White House has not responded to CNN's request for comment.
The President dismissed the reporting on Thursday morning, rhetorically asking if there is "anybody dumb enough to believe" it.
"Virtually anytime I speak on the phone to a foreign leader, I understand that there may be many people listening from various U.S. agencies, not to mention those from the other country itself. No problem!," he tweeted.
"Knowing all of this, is anybody dumb enough to believe that I would say something inappropriate with a foreign leader while on such a potentially 'heavily populated' call. I would only do what is right anyway, and only do good for the USA!" Trump said.
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