"We find the appellant's remaining arguments to be without merit. Therefore the District Court's detention order is affirmed," the document said.
A judge sent Manafort to jail on June 15 to await his trial due to allegations of witness tampering while out on bail. Special Counsel Robert Mueller alleged that Manafort was trying to convince two potential witnesses to lie to investigators about their work for the Ukrainian government.
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In October, Special Counsel Robert Mueller indicted Manafort on banking and tax-fraud charges related to laundering more than $30 million worth of income, including for work he did in Ukraine from 2006 to 2014. Manafort has also been charged for acting as an unregistered foreign agent and making false statements.
The former Trump campaign manager’s trial in Virginia started earlier on Tuesday. Manafort pleaded not guilty to the charges.