In an unusual letter to Congress this week, the Department of Homeland Security’s inspector general says a report he submitted more than six weeks ago on the chaotic implementation of President Donald Trump’s travel ban executive order has gone down a bureaucratic black hole.

“I’m very troubled by this development,” wrote Inspector General John Roth, warning that the Trump administration is likely to invoke various executive privileges to avoid releasing some or all of the report, a move he says will “significantly hamper” his ability to hold the department accountable.

Roth says that on Oct. 6 he submitted an 87-page report on the travel ban’s implementation based on more than 100 interviews and tens of thousands of pages of government documents. But the Trump appointees running the DHS have yet to even release an estimate as to when and how much of the report will be made public. DHS leadership has so far refused to say whether they will invoke what’s known as the “deliberate process privilege” as justification for keeping the report secret—an exemption usually reserved for Freedom of Information Act requests.

Roth warns that invoking the exemption in this case could “mask discovery of decisions made based on illegitimate considerations, or evidence of outright misconduct.”

Though he cannot yet reveal his full findings, Roth does say that Trump’s Customs and Border Protection “appears to have violated at least two separate court orders” regarding the travel ban, which is currently on hold after multiple federal courts found it unconstitutional. He also revealed in his letter that the CPB was not given a heads up about the travel ban before Trump signed the executive order in late January, and that they couldn’t answer even basic questions about the scope of the order or its legal status, leading to chaos and mass protests at airports around the country.

Agents in Los Angeles, for example, learned about the court injunction on the travel ban by watching television, and improperly turned away travelers because they did not receive guidance from their superiors.

Read Roth’s full letter below: