A Russian spy at the center of a secret operation to smuggle high-tech weapon components into Russia has left Japan after his activities were disclosed by The New York Times, a senior Ukrainian intelligence official said Thursday.

The operative, Maksim Vladimirovich Filchenkov, 49, had been working undercover in Japan as an employee of Russian state airline Aeroflot. Filchenkov’s role had been the focus of a Times investigation into how Russia exploited Japan’s weak espionage laws.

Filchenkov’s departure was first reported by Yomiuri Shimbun, a major national newspaper in Japan. The newspaper said the Russian exited Japan after the Times published its investigation July 12. The Ukrainian official who confirmed the spy’s departure did so on condition of anonymity because he was not authorized to discuss intelligence publicly.