(CNN) A federal judge expressed deep skepticism Friday of special counsel Robert Mueller's investigation in the bank fraud case against former Trump campaign chairman Paul Manafort, at one point saying he believes that Mueller's motivation is to oust President Donald Trump from office.
Although Mueller's authority has been tested in court before, Friday's hearing was notable for District Judge T.S. Ellis' decision to wade into the divisive political debate around the investigation.
"You don't really care about Mr. Manafort's bank fraud," Ellis said to prosecutor Michael Dreeben, at times losing his temper. Ellis said prosecutors were interested in Manafort because of his potential to provide material that would lead to Trump's "prosecution or impeachment."
Prosecutors have not disclosed that they're interested in having Manafort flip, but they have indicated that they continue to investigate him after his former deputy Rick Gates agreed to cooperate.
"That's what you're really interested in," Ellis said, citing how prosecutors regularly turn cooperators in drug cases. He was appointed to the bench in Virginia by President Ronald Reagan in 1987.
Ellis repeated his suspicion that Mueller's office was after Trump several times in the hourlong court hearing. He said he'll make a decision at a later date about whether Manafort's case can go forward.
Manafort has asked the judge to review Mueller's authority to bring charges in an investigation that began well before the special counsel's appointment and focused on actions years before the campaign.
Though he faces another criminal case in DC federal court, Manafort refused the prosecutors' earlier request to move these charges out of Ellis' district and combine them with the DC case. Defense lawyers often use approaches like Manafort's to gamble for a sympathetic judge or jury -- and the DC federal judge has been much harsher toward Manafort's requests in hearings.
Though Ellis largely skewered the special counsel's office on Friday, he also acknowledged to Manafort's lawyer the Justice Department's internal oversight and the detailed August 2 memo commissioning Mueller to investigate Manafort for his Ukrainian ties, which the special counsel's office allege connect him to Russians.
Ellis expressed his concern with past independent investigations and asked how Manafort's case could connect to Russian influence in the 2016 US presidential election. Dreeben gave little new information about the scope of Mueller's investigation and Manafort's Russian ties, but offered that both the Justice Department's national security and tax divisions had signed off on Manafort's charges.
"We don't want anyone in this country with unfettered power. It's unlikely you're going to persuade me the special prosecutor has power to do anything he or she wants," Ellis told Dreeben. "The American people feel pretty strongly that no one has unfettered power."
Manafort's charges in Virginia relate to bank fraud and other financial allegations from years ago. He has pleaded not guilty.
When Dreeben answered Ellis' question about how the investigation and its charges date back to before the Trump campaign formed, the judge shot back, "None of that information has to do with information related to Russian government coordination and the campaign of Donald Trump."
At one point, Ellis posed a hypothetical question, speaking as if he were the prosecutor, about why Mueller's office referred a criminal investigation about Trump's personal attorney Michael Cohen to New York authorities and kept the Manafort case in Virginia.
They weren't interested in it because it didn't "further our core effort to get Trump," Ellis said, mimicking a prosecutor in the case.
Mueller's prosecutors will have to turn over a full, unredacted version of the August 2 memo that Deputy Attorney General Rod Rosenstein used to describe the criminal allegations Mueller's team could investigate, Ellis ordered.
The judge said he would like to see the full memo, which prosecutors submitted to the court in Virginia and in Washington with more than a page of redactions.
The visible part of the memo says Mueller should investigate allegations about Manafort's financial relationship with former Ukrainian politicians, and that he may have assisted Russia with attempts to interfere in the presidential election. The redacted portion appears to outline several other legs of the ongoing Russia probe.
Ellis said prosecutors may present the full classified memo to him under seal -- without showing Manafort its additional details -- in two weeks.
Mueller's prosecutors have argued this memo gives them the authority to bring cases against Manafort related to his work in Ukraine.
Manafort is charged in Virginia with financial violations related to his lobbying work in Ukraine prior to joining Trump's 2016 campaign. Dreeben said they had to "follow the money" and find Manafort's contacts with Russians through the Ukrainian work and his financial dealings as part of their investigation.
He lost a civil suit making similar complaints about the special counsel's investigation last week. Manafort had filed a lawsuit in Washington claiming Rosenstein and Mueller exceeded their authority in charging him with alleged crimes he said had nothing to do with the 2016 campaign.
DC District Judge Amy Berman Jackson dismissed that lawsuit, saying a civil case was "not the appropriate vehicle" for objecting to either past or future actions by a prosecutor.
Manafort faces five charges in the case brought by Mueller's prosecutors in DC federal court, including money laundering and foreign lobbying violations.