The first criminal charges have been approved by a U.S. federal grand jury in the investigation into the Trump election campaign’s possible ties to Russia according to multiple reports.

A judge ordered the indictment sealed, so it’s not known what the charges are and who is involved.

Independent Counsel Robert Mueller has been investigating Trump’s presidential campaign, including the financial dealings of former National Security Advisor Michael Flynn and former campaign manager Paul Manafort.

Trump has denied that his campaign colluded with the Rusians and calls the investigation a witch hunt.