Ukrainian police have arrested the head of the state-run energy company Naftogaz, Yevhen Bakulin, in connection with a corruption investigation.
Interior Minister Arsen Avakov, in a statement on Facebook, said the police were conducting three separate investigations into suspected corruption in the natural-gas industry that may have cost the state some $4 billion.
Avakov said Bakulin was suspected of heading a "criminal group" whose members include other senior current and former Ukrainian government members.
There were no more immediate details on the police investigations.
Based on reporting by Reuters and AFP