Paul Manafort's bookkeeper says former Trump campaign chairman approved 'every penny' of his personal expenses

Paul Manafort's bookkeeper testified Thursday that the former Trump campaign chairman kept her in the dark about the foreign bank accounts he was using to buy millions in luxury items and personal expenses.

But he otherwise approved "every penny" of the personal bills she paid for him, said Heather Washkuhn of the accounting firm NKFSB.

Washkuhn's testimony appeared to undercut an argument by Manafort's defense attorneys that he can't be responsible for financial fraud because he left the details of his spending to others, including his longtime associate Rick Gates. Washkuhn said Gates was only involved in Manafort's business dealings, not his personal expenses.

When it came to personal expenses, Manafort "approved every penny of everything we paid," Washkuhn told jurors.

Manafort faces charges of bank fraud and tax evasion that could put him in jail for the rest of his life. It's the first courtroom test of the work of special counsel Robert Mueller, who is tasked with looking into Russia's efforts to interfere with the U.S. election and whether the Trump presidential campaign colluded with Moscow to sway voters.

While the question of collusion remains unanswered, Manafort's financial fraud trial has exposed the lucrative and secret world of foreign lobbying that made Manafort rich.

Related: Paul Manafort’s trial for bank and tax fraud charges

Other witnesses testifying this week said Manafort paid them millions from the offshore accounts tied to foreign shell companies for landscaping, expensive clothing and even a Karaoke machine.

When prosecutor Greg Andres read off some of the companies to Manafort's bookkeeper, she said Manafort never told her about them. She said she would have documented them for tax purposes if he had.

The federal judge overseeing the trial has questioned the hundreds of exhibits prosecutors want to submit as evidence of Manafort's lavish spending.

U.S. District Judge T.S. Ellis III said the money is relevant, but that he doesn't see the need for prosecutors to "gild the lily," especially considering Manafort's lawyers have not disputed that their client spent his money on luxury items.

Manafort's defense attorneys have signaled they will pin blame for any illegal conduct on Gates. He pleaded guilty earlier this year and agreed to cooperate with the investigation, making him the government's star witness. He is expected to testify at some point in the trial, which could last weeks.

Prosecutor Greg Andres argued that documenting Manafort's spending for the jury was important to the case.

"Judge, this is not an effort to prove Mr. Manafort lived lavishly," Andres said. "It's evidence of his income."

The proceedings have caught the attention of President Donald Trump. On Wednesday, he defended his 2016 hiring of Manafort and suggested Manafort was being treated worse than mobster Al Capone.

White House press secretary Sarah Huckabee Sanders said the president indeed felt Manafort had been treated unfairly.

"Why didn't government tell me that he was under investigation," Trump tweeted Wednesday. "These old charges have nothing to do with Collusion - a Hoax!"

Manafort has a second trial scheduled for September in the District of Columbia. It would address allegations that he acted as an unregistered foreign agent for Ukrainian interests and made false statements to the U.S. government.

Prosecutors told Ellis they expect to rest their case next week, noting that they are "ahead of schedule."