A legal battle that appears to involve Special Counsel Robert Mueller's investigation has reached the Supreme Court.

Supreme Court Chief Justice John Roberts Jr. on Sunday night ordered a weeklong pause on an ongoing subpoena fight, which may be the first known incidence of the high court weighing in on legal proceedings related to the Mueller probe into alleged Trump campaign collusion with Russia.

Roberts temporarily stayed an order holding an unnamed foreign government-owned company in contempt of court and accruing financial penalties for every day it does not comply with a subpoena the company has been challenging for months.

The stay will give the Supreme Court seven days to decide if the justices want to intervene in the case, and it could be the first time the full court hears a completely sealed court case, according to CNN.

The firm fighting the subpoena asked the Supreme Court to intervene after a D.C. Circuit Court panel ruled Tuesday that it was not immune to subpoenas because of its connection to a foreign government and the laws in the company's home country, according to Politico.

Court filings in this case have been short on details and shrouded in secrecy for months.

A filing last week was the first to provide a few details about the party challenging the subpoena. The unnamed firm was previously thought to have been an individual — which some speculated was President Donald Trump himself — and it has been resisting subpoenas to appear before a grand jury since the summer.

In October, Politico first reported that an ongoing but sealed legal battle appeared to involve Mueller's prosecutors. A reporter for the media outlet at the D.C. court clerk's office heard a person connected to the appeal request a copy of the special counsel's latest filing in the case in October.

Politico said that court personnel made the unusual decision to order journalists to leave the floor where lawyers were presenting their positions when this case was argued in District Court last week in a closed courtroom.

A spokesman for Mueller's office declined to comment on the dispute Sunday, Politico said.