WASHINGTON: A US federal judge on Friday ordered Paul Manafort, President Donald Trump's former campaign manager, to go to jail ahead of his trial on money laundering, tax and bank fraud charges.

Judge Amy Berman Jackson revoked Manafort's bail over claims he was tampering with witnesses in the case against him brought by special prosecutor Robert Mueller, who is investigating possible collusion between Trump's campaign and Russia.

Manafort had been under house arrest while awaiting trial later this year.

Mueller, who is investigating Russian interference in the 2016 presidential election, filed new obstruction of justice charges against Manafort last week.

The new indictment came four days after prosecutors said Manafort had tried to contact two witnesses in his money laundering and bank fraud case via Russian fixer Konstantin Kilimnik to persuade them to make certain representations to investigators.

Kilimnik, a former army-trained linguist with alleged ties to Russian intelligence, was included in an updated indictment of Manafort that accused both of witness tampering.

The indictment took the number of people indicted by the 13-month-old investigation by Mueller to 20, with three companies also facing charges.

Trump has denounced the Mueller probe as a political "witch hunt" and denied there was any collusion with Russia by members of his election campaign.