This courtroom sketch depicts Rick Gates, right, answering questions by prosecutor Greg Andres as he testifies in the trial of Paul Manafort, seated second from left, at the Alexandria Federal Courthouse in Alexandria, Va., Monday, Aug. 6, 2018.

Special counsel Robert Mueller's team of U.S. attorneys told a federal judge that they plan to rest their case against former Trump campaign chairman Paul Manafort by Friday, after days of salacious testimony from Manafort's ex-business partner, Rick Gates.

Gates had been pushed to admit at least one extramarital affair from a decade earlier under intense cross-examination from defense attorney Kevin Downing. The lawyer later suggested that Gates, as part of his "secret life," had maintained four separate affairs using a London apartment paid for with funds embezzled from Manafort.

Prosecutors objected before Gates had a chance to respond to Downing's suggestion and no further questions were asked about his adulterous behavior. But while Gates had already admitted to stealing "hundreds of thousands" of dollars from Manafort, he denied using that stolen money to support his infidelity.

Manafort's beleaguered protege testified under a plea deal struck with the special counsel in February, which dropped many of the charges against him in exchange for his full cooperation with the probe of Russian interference in the 2016 election and potential collusion by the Trump campaign.

Manafort and Gates had both been charged with financial crimes, including bank fraud and filing false income tax returns, in indictments obtained by the special counsel. Manafort, 69, has pleaded not guilty to all charges, and could face up to 30 years in prison for each count of the most serious charges if convicted.

Prosecutors seek to show that Manafort intentionally broke the law to hide income from the U.S. that he earned while working for Ukrainian President Viktor Yanukovych's pro-Russian Party of Regions. They allege that he resorted to bank fraud to continue funding his opulent lifestyle when Yanukovych was removed from power in 2014.

The defense has centered its case on Gates, 46, accusing him of deceiving Manafort and breaking the law in the process in order to embezzle money from his boss.

The trial, which is the first to be brought by Mueller's team, is not directly related to the Trump campaign or Russia's election meddling. But President Donald Trump's name came up in court nonetheless. Gates testified that Manafort recommended a banker who reportedly loaned him $16 million be appointed Trump's secretary of the Army.

"We need to discuss Steve Calk for Sec of the Army," Manafort wrote in a November 2016 email to Gates after the election. Manafort was Trump's campaign chairman until August 2016, but Gates stayed on and assisted during the post-election transition phase.

After Gates left the stand, the government brought forward two more witnesses from the FBI and IRS to testify about how Manafort moved money through overseas accounts.

At the end of the court session Wednesday, prosecutors told presiding Judge T.S. Ellis that they planned to call eight more witnesses.