Paul Manafort

Updated at 4:20 p.m. ET

Apparent Russian agents began reaching out to Donald Trump's presidential campaign as early as March 2016, the Justice Department established in documents released Monday, with appeals for partnership and offers of help including "dirt" on Trump's opponent, Hillary Clinton.

That case is made in charging documents in the case of then-Trump foreign policy adviser George Papadopoulos, who pleaded guilty to lying to the FBI.

Updated at 3:40 p.m. ET

Paul Manafort, President Trump's former campaign chairman, has been indicted on federal charges that range from conspiracy against the United States to conspiracy to launder money. He was taken into federal custody Monday morning, along with his longtime deputy.

In a court hearing around midday, both Manafort and his co-defendant, Rick Gates, pleaded not guilty.

A Russian billionaire paid former Trump campaign chairman Paul Manafort millions of dollars to boost the interests of Russian President Vladimir Putin, the Associated Press reports. The new allegations arise months after Manafort resigned from the campaign amid concerns over his work for a pro-Russian political party in Ukraine.