Mr. Manafort’s finances also intersected with companies of Mr. Vanagels and another Latvian whose name was used as a director, Stan Gorin. Among the murky transactions these companies engaged in was an $18 million deal to sell Ukrainian cable television assets to a partnership put together by Mr. Manafort, called Pericles, and financed by a Russian oligarch, Oleg V. Deripaska, according to a Cayman Islands lawsuit and Cypriot corporate records.
Milltown Corporate Services, a front company in Mr. Gorin’s name, for a time controlled the television assets.
In another notable case, the police in Ukraine last year questioned a barefoot man, Arkady Kashkin, who during interrogation accepted their offer of slices of pizza. He turned out to be named as a director of one of several related companies that had bought $1.5 billion in Ukrainian bonds, according to court records.
In that case, first reported by Al Jazeera, Ukrainian prosecutors said that an oligarch who has since fled to Russia, Serhiy V. Kurchenko, was the actual manager of the company registered in Mr. Kashkin’s name. A judge fined Mr. Kashkin for willingly allowing his identity to be used in fraud.
Neocom Systems Limited, Mr. Kaseyev’s company, which was opened a decade ago in the Central American nation of Belize, surfaced in relation to Mr. Manafort’s dealings in early 2017, several months after the longtime Republican Party strategist had been pushed out as Mr. Trump’s campaign manager over his Ukraine work.
The invoice had been left in the Kiev office of Mr. Manafort’s political consulting business, Davis Manafort International. In the invoice, Mr. Kaseyev’s name is transliterated into English as Evgeniy Kaseev.
Mr. Leshchenko, the Ukranian lawmaker, publicized the find after first providing the originals to the F.B.I. Mr. Leshchenko said that the company was a front and that Mr. Kaseyev had no control over its operations.