Establishment of illegal schemes to legalize amber and the involvement of Verkhovna Rada of Ukraine deputies Maksym Poliakov and Boryslav Rozenblat represents the first joint operation of the National Anti-corruption Bureau of Ukraine (NABU) and the U.S. Federal Bureau of Investigation (FBI), NABU chief Artem Sytnyk has said.

Sytnyk said the joint investigation began a year ago.

"This is the first case involving agent operations," Sytnyk said at a briefing in Kyiv with Special Anti-corruption Prosecutor's Office (SAPO) chief Nazar Kholodynytsky on Tuesday.

"It is a pleasure for me to say that this is the first operation conducted jointly with the FBI, pursuant to the assistance memorandum signed by NABU and the FBI," Sytnyk said.