The Supreme Court on Tuesday refused to block a grand jury subpoena that may be part of special counsel Robert Mueller’s investigation. The subpoena for information was issued to an unidentified company owned by a foreign government.

The justices issued a brief order declining to get involved in the subpoena dispute, rejecting a request from the company. All the documents in the case were filed under seal, but the court’s docket reflects the filings and the Supreme Court order.

A three-judge panel of the federal appeals court in Washington had in December upheld the issuance of the subpoena and a contempt order issued by a district court judge when the company failed to comply. The district court imposed and the appeals court upheld a fine in connection with the company’s refusal to comply.

Chief Justice John Roberts had put a hold on the fine and the company’s compliance, but the court’s action Tuesday removed that hold.

The unsigned opinion from the appellate panel revealed that the subpoena had been issued to a company owned by a foreign government, which has not been identified. The company had argued that it was immune from being subpoenaed under the Foreign Sovereign Immunities Act and that complying would require it to violate its country’s own laws.

Both Politico and The Washington Post have reported that the subpoena apparently relates to the Mueller investigation.

The case has been shrouded in secrecy as it has moved through the court system. Federal marshals closed an entire floor of the federal courthouse in Washington last month when the case was argued before the three-judge appellate panel. The move stymied the efforts of a group of about 15 reporters to see whether any Mueller team members or other participants had entered the hearing room.

Also on Tuesday, the company asked the Supreme Court for permission to file a sealed appeal for a full review of the case, with a redacted version available to the public. The justices have yet to act on that request.

(AP)