The Justice Department inspector general’s office has told witnesses who are set to review draft sections of its long-awaited report on the FBI investigation of President Donald Trump’s 2016 campaign that they will not be allowed to submit written feedback – one in a series of unusual restrictions that some fear could make the final document less accurate, people familiar with the matter said.

As is the case in most inspector general probes, witnesses are being invited to review draft sections of the report and offer comments and corrections, the people said. But – unlike most cases – they are being told that those comments must be conveyed verbally, the people said.

Even though Attorney General William Barr and other officials have been working in recent weeks to determine what should be redacted from the report as classified or private information, people familiar with the process said that the entire draft document is marked “Top Secret,” so anyone who discusses its contents outside a secure government room could be committing a crime.

Witnesses, they said, are being asked to review their sections in a secure area, after signing nondisclosure agreements, according to people familiar with the matter. The witnesses have also been told they will not be allowed to remove any notes they make about the document, the people said.

The moves have left some witnesses concerned that their objections might not be recorded precisely and incorporated into the inspector general’s findings, the people said. The witnesses, they said, are also concerned that the process gives the inspector general complete control in characterizing any comments witnesses make – and leaves witnesses with no ability to create a paper trail that might help them show that their words were captured inaccurately.

The people spoke on the condition of anonymity because of the political and legal sensitivity of the matter. A spokeswoman for the inspector general declined to comment.

The inspector general is aiming to complete the witness reviews by Nov. 21, though release of the report may wait until after the Thanksgiving holiday, these people said.

Democrats and Republicans alike have eagerly awaited release of Inspector General Michael Horowitz’s report, hopeful that the Justice Department’s internal watchdog will validate their views on the law enforcement investigation that dogged the first two years of Trump’s presidency.

Conservatives have said a medley of wrongdoing occurred during the investigation, which would eventually be taken over by special counsel Robert Mueller, and they are likely to seize on any criticism that Horowitz directs at those involved in the probe. Some Trump supporters have referred to the investigation as an attempted “coup.”

Democrats, meanwhile, hope Horowitz will disprove various conspiracy theories that have been offered about the case, and refute Trump’s assertion that Mueller’s probe was a “witch hunt” tainted by political bias against the president.

The report’s release is also likely to be a major credibility test for Barr, who has previously suggested impropriety on the part of the FBI. With Horowitz’s review ongoing, Barr earlier this year tapped a federal prosecutor in Connecticut – U.S. Attorney John Durham – to separately explore whether the intelligence activities aimed at people tied to the Trump campaign were lawful. Durham’s investigation is exploring potential crimes, officials have said.

Barr said this week that public release of the inspector general report is “imminent,” though he provided no specific date. People familiar with the matter said witnesses are scheduled this week and next to review drafts and offer feedback – generally the last step the inspector general takes before making the document public.

It is unclear what Horowitz has concluded. Witnesses have been asked about an array of topics, though investigators seem keenly focused on the FBI and Justice Department’s applications to the Foreign Intelligence Surveillance Court to monitor the communications of a former Trump campaign adviser, Carter Page, people familiar with the matter said.