Mysterious case linked to the Mueller probe hits the Supreme Court -- and could soon go public
Special Counsel Robert Mueller could be opening a new stage in the Russia collusion investigation. (AFP/File / Saul LOEB)

The U.S. Supreme Court is set to review a filing in the Mueller probe that might reveal the mystery company—linked to a foreign government—that reportedly failed to comply with a subpoena, Bloomberg reports.

Previously, an appeals court ruling upheld fines against the company.

According to the docket, the identity of the company might soon be made public.

"So far as we know, the Court has never had a sealed argument before all nine Justices," Supreme Court analyst Steve Vladeck told CNN.

"They can keep parts of the record and briefing sealed, and often do, such as in cases implicating trade secrets. But there's no procedure in the court's rules for having the whole case briefed, argued and decided under seal. The only times I'm aware of in which parties tried it, the court denied certiorari," or the review of the case.