Special counsel Robert Mueller asked a judge to give immunity to five people who may testify at the bank-fraud trial starting next week against Paul Manafort, President Donald Trump's former campaign chairman.

Mueller didn't identify the witnesses, who haven't been charged. The five would invoke their constitutional right against self-incrimination and remain silent unless Judge T.S. Ellis III grants them immunity, prosecutors said Tuesday in a court filing in federal court in Alexandria, Virginia. Their names will be made public only if they are called to testify, according to the filing.

"Disclosing the motions would reveal those individuals' involvement in the investigation and the trial, thereby creating the risk of undue harassment," prosecutors wrote. "Such concern potentially would be heightened by the additional revelation that they have invoked their privilege against self-incrimination."

Prosecutors asked Ellis to seal five separate motions about the potential witnesses and unseal any of them if they are called to testify.

Manafort, 69, is accused of bank fraud and tax crimes in the Alexandria case. He would be the first of 32 people charged by Mueller to go to trial. He faces a Sept. 17 trial in Washington on charges of money laundering, obstruction of justice and acting as an unregistered foreign agent of Ukraine.

The cases are U.S. v. Manafort, 17-cr-201, U.S. District Court, District of Columbia (Washington), and 18-cr-83, U.S. District Court, Eastern District of Virginia (Alexandria).