Special Counsel Robert Mueller apparently isn’t quite done with his investigation into Russian interference into the U.S. presidential election and possible collusion with the Trump campaign. A federal judge has granted Mueller’s request to extend the term of the grand jury hearing evidence in his criminal inquiry for up to six months, according to several media reports.

The term of the jury, impaneled in Washington in early July 2017, was set to expire this weekend. Extensions for up to six months are routinely granted if a judge is convinced that it serves the public interest.

Chief Judge Beryl Howell of the U.S. District Court for the District of Columbia approved the extension, The New York Times reported, though she offered no details concerning the reason why.

Grand juries hear evidence in cases, and the 23 members of the secret panels vote on whether or not to approve indictments presented by a prosecutor.

This grand jury, identified as 17-1, has already returned several indictments related to the Mueller investigation, including charges against former Trump campaign chairman Paul Manafort and former campaign deputy Rick Gates. It also returned indictments against three Russian companies and 25 Russians, including several military intelligence officers, charging them with hacking and other online activity tied to the presidential election.

The extension is likely an indication that there could be more indictments. GOP political operative Roger Stone and right-wing conspiracy theorist and writer Jerome Corsi — both supporters of President Donald Trump — have already said they were threatened with indictments by Mueller’s team. The Washington Post reported in November that Corsi was in plea negotiations with Mueller.

A company owned by a foreign country, possibly a bank, is reportedly fighting a grand jury subpoena apparently related to Mueller’s investigation. The challenge is now before the U.S. Supreme Court, CNN has reported.

Just Thursday prosecutors asked a federal judge to allow submission of a sealed brief concerning a “matter occurring before the grand jury.” No details were provided in the public motion, but the request was granted on Friday, Politico reported.

Prosecutors have the option of using a new grand jury once the term of a previously established one expires. But there are advantages for a prosecutor to have an experienced panel with a deep background in an investigation.