Boeing will face sanctions after breaking an agreement by disclosing details of an investigation into the 737 Max 9 door panel that blew out in mid-air, the National Transportation Safety Board said Thursday.

The agency said in a statement that Boeing “blatantly violated NTSB investigative regulations” at a media briefing on Tuesday by providing investigative information that hadn’t been cleared for release and speculating about the cause of the incident nearly six months ago.

The Alaska Airlines Flight lost a door panel Jan. 5 while traveling at 16,000 feet, some 10 minutes before its scheduled arrival time in Portland, Oregon. The mishap plunged Boeing into crisis and raised ongoing questions about safety concerns on other aircraft models, now the subject of multiple federal investigations.

The NTSB said that an unidentified Boeing executive spoke Tuesday about improvements at Boeing’s commercial airplanes division, including “analysis of factual information previously released.”

Boeing also mischaracterized the investigation, the statement said, by describing it as an attempt to find the person responsible for fitting the door plug.

“The NTSB is instead focused on the probable cause of the accident, not placing blame on any individual or assessing liability,” the statement said.

According to the board, this means Boeing has broken the party agreement it signed at the start of the investigation.

Boeing did not immediately respond to an overnight request for comment from NBC News.

In a stinging rebuke, the agency said that because the company has been a party or active participant that has contributed evidence in many NTSB investigations, “few entities know the rules better than Boeing.” 

As a result, it said, Boeing will remain a party in the board’s investigation but will no longer be able to access investigative information it gathers in making a full factual record of the accident.

The NTSB asked for a transcript of Tuesday’s meeting, which it said showed that the company “provided non-public investigative information to the news media that NTSB had not verified or authorized for release.”

The board also accused Boeing of “offering opinions and analysis on factors it suggested were causal to the accident.”  

The board said it would also subpoena Boeing to appear at an investigative hearing Aug. 6 and 7 in Washington, where the company’s attorneys and executives will not be able to ask questions.

The NTSB said it would coordinate with the Justice Department’s Fraud Division by providing details of this week’s alleged unauthorized information release.

Boeing is also accused by the DOJ of violating a 2021 deferred prosecution agreement that shielded it from criminal charges related to fatal 737 Max crashes.

The company said it believed it had honored the terms of that agreement and would engage with the DOJ “with the utmost transparency, as we have throughout the entire term of the agreement.”