The indictment, filed in Washington federal court by Special Counsel Robert Mueller, said Manafort retained the so-called Hapsburg Group of onetime politicians, to "take positions favorable to Ukraine, including by lobbying the United States."
The group, which operated in 2012-2013, was managed by an unnamed "former European chancellor," who along with other members of the group lobbied US legislators and White House officials, it said.
They were to "appear to be providing their independent assessments of government of Ukraine actions, when in fact they were paid lobbyists for Ukraine," according to the indictment.
The group was meant to "act informally and without any visible relationship" to the Ukraine government, a memorandum written by Manafort in June 2012 read.
Backed by Moscow, the billionaire Yanukovych was eyed suspiciously at the time in much of Europe for his pro-Russia stance and widespread accusations of deep corruption.
He was overthrown in the popular uprising of 2014 and exiled to Russia. After that, Manafort stopped working for him, returned to the United States and, in 2016, joined Trump's election campaign.
While the latest indictment did not charge Manafort with any crime specifically tied to the Hapsburg Group, those activities were cited to show Manafort had been actively lobbying for Ukraine and had broken laws by not registering as such in the United States.