This was reported by RIA Novosti with reference to Korban's statement in social networks.
He said that he was at the entrance to Ukraine at the Smilnytsia border crossing point.
“The passport of a citizen of Ukraine was confiscated from me, an act was issued.
They don’t let me go home to Ukraine,” Korban said.
He called the incident a misunderstanding and asked Ukrainian President Volodymyr Zelensky to help him.
Earlier in Ukraine, the law "On the prevention of threats to national security associated with excessive influence of persons with significant economic and political weight in public life (oligarchs)" came into force.