Paul Manafort had "a huge dumpster of hidden money" abroad, a prosecutor has said, urging a jury to convict the former Trump campaign chief on financial fraud charges based more on a paper trail of evidence than the testimony of a former protege.

Key points: Paul Manafort has been charged with tax and bank fraud as well as failing to disclose foreign bank accounts

Paul Manafort has been charged with tax and bank fraud as well as failing to disclose foreign bank accounts He could face eight to 10 years in prison if found guilty on all charges

He could face eight to 10 years in prison if found guilty on all charges The jury is expected to begin deliberating on a verdict on Thursday morning (local time)

Special assistant US attorney Greg Andres gave his closing statement in federal court in Virginia, where Mr Manafort is on trial on tax and bank fraud charges, along with failing to disclose foreign bank accounts.

The jury is expected to begin deliberating on a verdict on Thursday morning (local time).

The trial is the first to come out of Special Counsel Robert Mueller's investigation of Russian meddling in the 2016 presidential election.

The charges involve tax and bank fraud, not possible collusion between Russia and Donald Trump's campaign for president.

A Manafort conviction would undermine efforts by Mr Trump and some Republican lawmakers to paint Mr Mueller's Russia inquiry as a political witch hunt, while an acquittal would be a setback for the special counsel.

The star witness against Mr Manafort has been viewed as Rick Gates, his former right-hand man, who was indicted along with Mr Manafort but pleaded guilty and agreed to cooperate with the Government.

The defence has portrayed Mr Gates as a lying thief who had his hand in the "cookie jar" and was only trying to reduce his own sentence.

Mr Andres argued that while Mr Manafort did not "choose a Boy Scout" as his associate, Mr Gates' testimony was corroborated by other evidence, including nearly 400 exhibits.

"The star witness in this case is the documents," he told the jury.

"That wasn't a cookie jar," he added, referring to the tens of millions of dollars Mr Manafort had overseas.

"It was a huge dumpster of hidden money in foreign bank accounts."

'Gates came in here and tried to get one over on you'

Rick Gates testifies during questioning in the bank fraud and tax evasion trial of Paul Manafort. ( AP: Dana Verkouteren )

Prosecutors said Mr Manafort, 69, tried to mislead bankers with doctored financial statements in 2015 and 2016 to get loans and wilfully failed to pay taxes on more than $US15 million ($21 million) that he earned as a political consultant in Ukraine.

Defence lawyers decided not to call any witnesses in the trial and Mr Manafort, a veteran Republican political operative, will not testify in his own defence.

In the defence's closing argument, Mr Manafort's lawyers argued that issues with his financial situation were known to the bankers before they extended the loans to him.

They also sought to emphasise the idea that Mr Manafort did not knowingly break the law — a requirement for conviction — and was rather failed by the bookkeepers, accountants and other professionals in whom he trusted his financial affairs.

"Sometimes the people we rely on are trustworthy. Sometimes they are not," lawyer Richard Westling said.

In its closing argument, the defence took aim at Mr Gates, who admitted in court to an extramarital affair.

He also said he helped Mr Manafort doctor financial statements, hide foreign income and evade hundreds of thousands of dollars in US income taxes.

Mr Manafort's attorneys have portrayed Mr Gates as living a secret life of infidelity and embezzlement.

Defence lawyer Kevin Downing told the jury that Mr Gates had shown himself to be a liar.

"He came in here trying to look all clean-shaven," Mr Downing said.

"He came in here and tried to get one over on you."

Mr Manafort made millions of dollars working for pro-Russian Ukrainian politicians before he took an unpaid position with Trump's campaign.

He was on the campaign team for five months and led it in mid-2016 when Mr Trump was selected as the Republican nominee for the presidential election.

Mr Manafort has been charged with tax and bank fraud as well as failing to disclose foreign bank accounts.

If found guilty on all 18 charges by the 12-person jury, he could face eight to 10 years in prison, according to sentencing expert Justin Paperny.

Mr Manafort also faces a second trial in September in Washington, where he is accused of failing to disclose lobbying for Ukrainian politicians, among other crimes.

Reuters