Derkach publicized documents which, as he said, "describe the mechanism of getting money by Biden Sr." at a press conference at Interfax-Ukraine's press center in Kyiv on Wednesday.

"This was the transfer of Burisma Group's funds for lobbying activities, as investigators believe, personally to Joe Biden through a lobbying company. Funds in the amount of $900,000 were transferred to the U.S.-based company Rosemont Seneca Partners, which according to open sources, in particular, the New York Times, is affiliated with Biden. The payment reference was payment for consultative services," Derkach said.

He also publicized sums that were transferred to Burisma Group representatives, in particular Hunter Biden, a son of the former U.S. vice president.