A former top FBI official in New York has been arrested over his ties to a Russian oligarch, law enforcement sources told ABC News Monday. He was arrested Saturday afternoon after he arrived at JFK Airport following travel in Sri Lanka, the sources said. McGonigal and Shestakov, who worked for the FBI investigating oligarchs, allegedly agreed in 2021 to investigate a rival Russian oligarch in return for payments from Deripaska, according to the Justice Department.