WASHINGTON — The Supreme Court refused on Tuesday to intercede in a mysterious fight over a sealed grand jury subpoena to a foreign corporation issued by a federal prosecutor who may or may not be Robert S. Mueller III, the special counsel investigating the Trump-Russia affair.

The court’s action means the corporation, which has not been identified, must provide information to the prosecutor or face financial penalties. The court’s two-sentence order gave no reasons and provided no details.

Almost everything about the case has been cloaked in secrecy. But a three-page order issued on Dec. 18 and a more detailed opinion studded with blacked-out passages issued on Tuesday after the Supreme Court acted, both from the United States Court of Appeals for the District of Columbia Circuit, provided a few hints.

Judges David S. Tatel and Thomas B. Griffith joined the appeals court’s unsigned majority opinion, and Judge Stephen F. Williams agreed with the outcome but not all of the majority’s reasoning.