WASHINGTON — Paul Manafort turned himself in to federal authorities Monday morning. The charges against Mr. Manafort, President Trump’s former campaign chairman were not immediately clear but represent a significant escalation in a special counsel investigation that has cast a shadow over the president’s first year in office. Also charged was Mr. Manafort’s former business associate Rick Gates, who was also told to surrender.
Mr. Manafort walked into the F.B.I.’s field office in Washington about 8:15 a.m. with his lawyer.
Mr. Manafort had been under investigation for violations of federal tax law, money laundering and whether he appropriately disclosed his foreign lobbying.
Mr. Manafort, a veteran Republican strategist, joined the Trump campaign in March 2016 to help keep delegates from breaking with Mr. Trump in favor of establishment Republican candidates. Mr. Trump soon promoted him to chairman and chief strategist, a job that gave him control over day-to-day operations of the campaign.
But Trump fired him, after reports that he received more than $12 million in undisclosed payments from Viktor F. Yanukovych, the former Ukrainian president and a pro-Russia politician. Mr. Manafort spent years as a political consultant for Mr. Yanukovych.
American intelligence agencies have concluded that President Vladimir V. Putin of Russia launched a stealth campaign of hacking and propaganda to try to damage Hillary Clinton and help Mr. Trump win the election.
The New York Times revealed in July that Mr. Manafort and others close to Mr. Trump met with Russians last year, on thepromise of receiving damaging political information about Mrs. Clinton.