The Supreme Court on Monday turned back a company locked in a secretive fight against Robert Mueller just days after the special counsel concluded his probe into Russian interference in the 2016 election.

In a brief order, the court said it would not review a decision by a federal appeals court in Washington that ordered the company, owned by an unknown foreign government, to comply with a subpoena or face a mounting daily fine, believed to be greater than $2 million at this point.

The legal battle stretches back to July, when a grand jury in Washington subpoenaed the company for information. The company sought to dismiss the subpoena, but was rejected twice in court before the Supreme Court looked at the matter.

In January, Chief Justice John Roberts declined to halt the daily fines as the court continued to review the case.

The dispute is believed to be the only time the nation's top court has weighed in on an element of Mueller's inquiry. That inquiry wrapped up last week.

Attorney General William Barr on Sunday told lawmakers in a four-page letter that Mueller did not find evidence of collusion between the president's campaign and Russia. Barr said there was not sufficient evidence to prosecute Trump for obstruction.

It takes four justices to agree to review a case. While justices' votes are not listed on the order, the company failed to secure that number, at least.

The case gained attention thanks in part to the unusual precautions taken to ensure the secrecy of those involved. Prosecutors working for the special counsel were not named in public documents until last month. Before that, Mueller was only believed to be involved because of comments overheard in a D.C. courthouse.

At one point, security personnel cleared an entire floor of reporters to preserve the identities of those involved in a hearing related to the case.

As a legal matter, the case concerned whether the company is immune to certain criminal penalties under the 1976 Foreign Sovereign Immunities Act.

In written arguments, attorneys for the unnamed company argued that the appeals court decision to enforce the subpoena, if left standing, would "throw international law into disarray."

But the Justice Department retorted that the company was not immune, and argued that accepting the company's position would allow foreign-owned companies to "flagrantly violate criminal laws."

The special counsel's office declined to comment.