relation to the Ukrainian government," prosecutor Serhiy Gorbatyuk told NPR in an interview.

Manafort declined to comment, only saying through his spokesman, Jason Maloni, that he hoped Ukrainian investigators would look into an alleged blackmail attempt against him.

Gorbatyuk heads an office charged with investigating the Yanukovych government, especially at the time of the bloodshed on the Maidan. Gorbatyuk says he is still waiting for an FBI response to multiple requests for help in questioning Manafort as a witness in another Yanukovych-era corruption case.

The 2014 Maidan revolution threw Ukraine into turmoil. Hundreds of thousands of Ukrainians took to the streets to protest Yanukovych's decision to reject an association agreement with the European Union and align Ukraine more closely with Russia. After the protests turned violent, Yanukovych fled to Russia, wherehe remains. In the ensuing power vacuum, Russia annexed Crimea and supported an armed uprising by pro-Kremlin separatists in eastern Ukraine.

It's not clear when Manafort last visited his Kiev office, which used to be in a century-old brick building on a quiet side street off the Maidan. But his name resurfaced last August, when the New York Times reported that it was included in secret "black ledgers" that appeared to document Yanukovych's cash payments to political allies. Shortly afterward, Manafort resigned as manager for Trump's presidential campaign.

The story didn't end there — at least not in Ukraine.

In March, Ukrainian lawmaker Serhiy Leshchenko released financial documents that he said were found in Manafort's former office and showed that on one occasion, Yanukovych used an offshore bank account and phony