Three attorneys representing former Trump campaign aide Rick Gates have withdrawn as counsel in the case.

According to a motion filed Thursday night in the U.S. District Court for the District of Columbia, lawyers Shanlon Wu, Walter Mack, and Annemarie McAvoy said they were withdrawing effective immediately, and the explanation for their departure is included in sealed documents.

The three attorneys were representing Gates against special counsel Robert Mueller’s indictment.

Mueller, who is investigating Russian meddling in the 2016 presidential election and possible collusion with the Trump campaign, unsealed the charges against Gates alongside Paul Manafort, Trump’s former campaign manager, last fall.

Prominent white-collar attorney Tom Green, who joined Gates’ defense team in late January, reportedly remains on as counsel.

CNN reported last week that Green was seen at Mueller's office twice the week prior.

Gates and Manafort both pleaded not guilty.