A federal judge is asking skeptical questions about Special Counsel Robert Mueller’s authority to bring charges against former Donald Trump campaign chairman Paul Manafort on tax and bank fraud charges.

Manafort’s lawyers argued at a hearing Friday in Alexandria, Va., that the charges are far afield from Mueller’s mandate to investigate Russian meddling in the 2016 election and whether any collusion occurred.

The Virginia indictment alleges Manafort hid tens of millions of dollars he earned advising pro-Russia politicians in Ukraine from the Internal Revenue Service, all occurring years before Trump ran for president.

Judge T.S. Ellis III said said Mueller should not have “unfettered power” in his Russia probe. He suggested the real reason Mueller is pursuing Manafort is to pressure him to provide evidence against Trump.

Ellis withheld ruling on dismissal of the indictment.

The judge questioned why Manafort’s case there could not be handled by the U.S. attorney’s office in Virginia, rather than the special counsel’s office.

He also asked the special counsel’s office to share privately with him a copy of Deputy Attorney General Rod Rosentein’s August 2017 memo elaborating on the scope of Mueller’s Russia probe. He said the current version he has has been heavily redacted.

The Virginia case is scheduled for trial in July.

Manafort is also charged in the District of Columbia, accused of conspiring against the United States, conspiring to launder money and failing to register as a foreign agent when he lobbied for the pro-Russia Ukrainian government.

The courtroom development came as Trump again told reporters he’d be eager to speak to Mueller as part of the probe. But he told them before departing for the National Rifle Association conference in Dallas that we would need to ensure that he’d be “treated fairly.”

Speaking to reporters on the South Lawn on Friday, Trump again called the investigation into whether members of his campaign and transition team colluded with Russia a “witch hunt.”