A jury in Virginia began deliberations in the trial of Paul Manafort, President Donald Trump's former campaign chairman who is facing bank and tax fraud charges that could put him behind bars for years.

Paul Manafort, 69, a veteran political consultant, made his fortune helping to bring pro-Russian politician Viktor Yanukovych to power in Ukraine in 2010.
Paul Manafort, 69, a veteran political consultant, made his fortune helping to bring pro-Russian politician Viktor Yanukovych to power in Ukraine in 2010. (AFP Archive)

A jury began deliberations on Thursday in the tax and bank fraud trial of Donald Trump's former campaign chief Paul Manafort after 12 days of riveting testimony featuring hidden bank accounts, betrayal and lavish spending on homes, cars and clothes.

Judge TS Ellis delivered final instructions to the six-man, six-woman jury before they retired to consider the 18 charges facing the once high-flying Republican political consultant.

"You may deliberate as long or as little as you like" Ellis told the jurors before they filed out of the federal courtroom in Alexandria, Virginia, clutching their black notebooks.

Manafort, 69, is accused of providing fraudulent statements to secure bank loans and failing to pay taxes on tens of millions of dollars he earned while advising Russian-backed politicians in Ukraine between 2005 and 2014.

The case stems from Special Counsel Robert Mueller's investigation into Russian interference in the 2016 presidential election.

Manafort is not charged with any crimes related to his brief time as Trump's campaign chief, but the trial is seen as an important test for the Mueller probe.

An acquittal would provide ammunition to the president and his allies to ramp up the pressure on Mueller to conclude his investigation into whether any members of the Trump campaign colluded with Russia.

Trump has repeatedly denounced the Mueller probe as a political "witch hunt" and denied there was any collusion with Moscow to help him defeat Democrat Hillary Clinton.

Prosecutors over the past 12 days outlined the various schemes allegedly used by Manafort to avoid paying taxes and hide bank accounts in Cyprus.

Defence attorneys sought for their part to cast doubt on the credibility of the prosecution's star witness, Manafort's former trusted deputy, Rick Gates, who took a deal from the government and turned against his former boss.

"This case is littered with lies," assistant US attorney Greg Andres told the jury in closing arguments on Wednesday. 

"Mr Manafort lied and lied again."

$18,500 python jacket

Andres said Manafort, who could face decades in prison, filed false tax returns between 2010 and 2016 to hide his earnings in Ukraine from US tax authorities.

The money was deposited in 31 foreign bank accounts, most of which were in Cyprus, and Manafort repeatedly failed to report their existence to his bookkeeper, his accountants and the Internal Revenue Service, the prosecutor said.

Manafort also filed false statements to obtain millions of dollars in loans from banks when he was facing financial difficulties after the Ukraine consulting dried up, he said.

Gates, during three days on the witness stand, outlined for the jury how he helped his boss hide his earnings offshore.

Defence attorneys sought to paint Gates as a liar, a thief and an adulterer, pointing out that he had pleaded guilty to his own crimes in the hopes of receiving a lesser prison sentence.

"This was someone Paul trusted," defence attorney Kevin Downing said.

During his testimony, Gates, 46, who is married and has four children, acknowledged stealing hundreds of thousands of dollars from Manafort and having an extramarital affair a decade ago.

"We don't ask you to like him," Andres, the prosecutor, said of Gates. He urged the jury to consider his testimony alongside that of the two dozen other witnesses called against Manafort.

Arguing for acquittal, Richard Westling, another defence attorney, said the government had failed to prove Manafort's guilt beyond a reasonable doubt.

Prosecutors provided evidence during the trial of Manafort's years of lavish spending – millions of dollars on luxury houses, Range Rovers, antique rugs and clothes, including an $18,500 python jacket.

But Andres said the case was "not about his wealth" but about the "overwhelming" evidence of Manafort's guilt.

"Mr Manafort knew the law and he violated it anyway," he said.

While Gates and several others indicted by Mueller have pleaded guilty, Manafort refused to cut a deal and insisted on having his day in court.

Manafort, who worked on the presidential campaigns of Republicans Gerald Ford, Ronald Reagan, George HW Bush and Bob Dole, was Trump's campaign chairman from May to August 2016.

He was forced to step down amid questions about his work for Ukraine's former pro-Russian leader Viktor Yanukovych and legal experts say he may be holding out hopes of a pardon from Trump.

Source: AFP