Ukrainian Prosecutor General Yuriy Lutsenko has said that if the operation by the National Anti-Corruption Bureau (NABU) at the State Migration Service of Ukraine was conducted jointly with the FBI, then this is a violation of the law.

"As I was informed, [NABU Director] Artem Sytnyk said in your studio that it was a joint operation by the NABU and the FBI. If he said this, then the question arises who authorized the operation of a foreign special service on Ukrainian territory," he said live on the 1+1 television channel late on Sunday, December 3.

He noted that FBI employees had been invited to Ukraine just once, after the murder of journalist Pavlo Sheremet.

"A joint operation, as he [Sytnyk] says, is an absolutely illegal action without respective legal procedures," he said.

According to Lutsenko, he understands "Mr. Sytnyk's desire to cover up his problems, but to cover them with foreign partners is childishness."