The FBI has documents and statements from two people showing Manafort attempted communication while he was out on bail, "in an effort to influence their testimony and to otherwise conceal evidence."

The prosecutors had also said that Manafort ghostwrote the op-ed with a longtime colleague "assessed to have ties" to Russian intelligence.

Manafort and Gates were charged on counts ranging from fraud to conspiracy, but it was the evidence made public Monday against George Papadopoulos that revealed ties between Trump’s inner circle and Russia.