WASHINGTON (Reuters) - The U.S. Supreme Court on Tuesday let an unidentified foreign government-owned company appeal under seal a grand jury subpoena possibly related to Special Counsel Robert Mueller’s probe into Russia’s role in the 2016 election, and the firm said a ruling against it would “wreak havoc” on American foreign policy.

FILE PHOTO: A worker clears snow from the steps outside of the U.S. Supreme Court in Washington, U.S., November 15, 2018. REUTERS/Leah Millis/File Photo

The case has remained a high-profile mystery, with the Supreme Court and lower courts declining to identify the company, the country that owns it or the purpose of the subpoena.

More details about the company’s legal arguments were revealed in redacted court papers made public after the nine justices permitted it to move forward with its appeal to the high court under seal, a process that keeps many facts about the matter secret. The company is facing a daily fine of $50,000 imposed by a U.S. federal judge in Washington for refusing to comply with a subpoena issued in the unidentified investigation.

Lawyers for the company urged the Supreme Court to take up the case, saying in the court papers that the lower court ruling it is contesting “would wreak havoc on American foreign policy - possibly alienating U.S. allies, undermining diplomatic efforts, and inviting reciprocal treatment abroad for American agencies.”

The legal question is whether the company is protected under the Foreign Sovereign Immunities Act, a law that allows foreign countries to avoid being sued in U.S. courts but does not cover commercial activities.

In the redacted court papers, the company said the Foreign Sovereign Immunities Act protects it not just in civil cases but also in criminal cases. The company also argued that foreign countries are immune from contempt findings.

As Mueller’s probe, which also is examining whether President Donald Trump’s campaign conspired with Moscow and whether he has committed obstruction of justice, already has implicated foreign entities, the subpoena could be linked to the investigation. Mueller’s office has declined to comment.

Mueller in February charged three Russian companies as part of a criminal and espionage conspiracy to tamper in the election to support Trump’s presidential campaign and disparage his Democratic opponent Hillary Clinton. Mueller also has charged a series of Russian individuals and has won guilty pleas from Trump campaign figures including its former chairman.

The U.S. Court of Appeals for the District of Columbia Circuit in its ruling against the company on Dec. 18, which was made public on Jan. 8, concluded “there is a reasonable probability the information sought through the subpoena here concerns a commercial activity that caused a direct effect in the United States.”

The appeals court ruling noted that the company has a U.S. office and that the company has said it has no relevant documents in the United States. The Supreme Court on Jan. 8 rejected the company’s emergency request seeking to put the fines on hold pending appeal.