Donald Trump's former campaign manager will be held in jail before his trial after a judge revoked his bail.
Paul Manafort pleaded not guilty to new charges of witness tampering when he appeared in court in Washington DC on Friday.
Judge Amy Berman Jackson decided to revoke his current bail conditions and sent him to jail before his trial, as a result of the new allegations.
She told him he had treated the court proceedings as "just another marketing exercise".
She said: "You have abused the trust placed in you six months ago."
Mr Manafort, 69, was previously under house arrest and forced to wear a GPS monitoring device.
Judge Jackson has previously refused to end the house arrest after Mr Manafort offered $10m in real estate as collateral.
According to the prosecution, Mr Manafort and his associate Konstantin Kilimnik attempted to tamper with the witnesses in the case, asking them to lie about the nature of their political work in Ukraine.
They say the two men asked the witnesses to say the political work was only carried out in Europe, and not the US, although the witnesses know this is not the case.
Mr Manafort's lawyers say he has not done anything wrong and accused prosecutors of conjuring a "sinister plot" out of "innocuous" contacts with witnesses.
Mr Trump tweeted: "Wow, what a tough sentence for Paul Manafort, who has represented Ronald Reagan, Bob Dole and many other top political people and campaigns. Didn't know Manafort was the head of the Mob. What about Comey and Crooked Hillary and all of the others? Very unfair!
"I've had to beat 17 very talented people including the Bush Dynasty, then I had to beat the Clinton Dynasty, and now I have to beat a phony Witch Hunt and all of the dishonest people covered in the IG Report…and never forget the Fake News Media. It never ends!"
Mr Manafort faces several charges related to his Ukrainian political work and money he funnelled through offshore accounts.
His lawyers filed a memo in court on Friday, written by a witness, which they say shows the nature of the Hapsburg group's work was European-focused.
However prosecution lawyers then filed a 2013 note from Mr Manafort to then-Ukrainian president Viktor Yanukovych which said he had designed a programme which used the Hapburg's members to lobby US politicians and influence American public opinion.
The charges stem from an investigation into Russia's alleged meddling in the 2016 election, which is being led by special counsel Robert Mueller.
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Manafort has been indicted in Washington DC and Virginia including a charge of conspiracy against the United States.
He faces two trials, one in Virginia due to begin on 25 July, and another in the nation's capital, scheduled to start in September.