Paul Manafort has pleaded not guilty to all the charges. (Reuters)

The first trial of Special Counsel Robert Mueller's Russia probe begins on Tuesday with Paul Manafort, a former chairman of U.S. President Donald Trump's campaign, facing charges that he hid tens of millions of dollars earned in Ukraine in offshore accounts and defrauded banks for loans.

The tax and bank fraud trial in a Virginia federal court will be the first test of Mueller's ability to win a conviction of a former Trump aide. Three other aides, including longtime Manafort business partner Rick Gates, have pleaded guilty and are cooperating with Mueller's probe.

Trump has vacillated between showing sympathy for Manafort and trying to distance himself. Manafort ran Trump's presidential campaign for three months and attended a June 2016 Trump Tower meeting with Russians that is a focal point of Mueller's probe into possible collusion between the campaign and the Kremlin.

A Manafort conviction would give momentum to Mueller, who has indicted or secured guilty pleas from 32 people and three companies since the probe started 14 months ago. An acquittal would support efforts by Trump and his allies to portray the probe as a "witch hunt" and waste of time and resources. Trump denies any collusion.

Manafort, 69, faces 18 criminal counts, which center on allegations that he hid much of the $60 million he earned in Ukraine in undisclosed overseas bank accounts and failed to pay taxes on it.

Prosecutors also accuse him of lying to U.S. banks to obtain real estate loans in a bid to maintain a lavish lifestyle after his client, former pro-Russia Ukrainian President Viktor Yanukovych, fell from power in 2014 and the money stopped.

Manafort has pleaded not guilty to all the charges.

While prosecutors have said they will not present evidence of collusion at this trial, they are seeking to provide details of Manafort's work in Ukraine, raising the possibility that new information about his Russian connections could emerge. Manafort has filed a motion to have details of that work excluded from trial.

T.S. Ellis, the judge overseeing the case, has called a hearing for Tuesday at 9 a.m. (1300 GMT) on whether that Ukraine-related evidence can be included. That will be followed by voir dire - the process of vetting jurors for bias - at 10 a.m.

The Virginia trial will be followed by a second one in Washington in September in which Manafort is charged with money laundering, failing to register as a foreign agent and witness tampering.

Manafort has pleaded not guilty to those charges, as well.

© Thomson Reuters 2018