Mikhail Slobodin, chief executive officer of VimpelCom Russia, will resign with immediate effect amid a corruption probe.

Russia’s Investigative Committee, the country’s chief investigative body, this week announced that it has detained Slobodin regarding bribery allegations with his prior employer, T Plus. The investigation concerns suspicious payments of over 800 million rubles (US$12.3 million).

Kjell Johnsen, head of major markets, will lead VimpelCom’s business in Russia with immediate effect. Johnsen, who joined VimpelCom to lead its major markets in August, has international expertise in senior roles across a variety of industries, with responsibility for markets such as Russia, Scandinavia, and Central and Eastern Europe.

Amsterdam-based telecommunications company Vimpelcom is no stranger to bribery allegations. In February, Vimpelcom and its wholly owned Uzbek subsidiary, Unitel, entered into resolutions with the U.S. government agencies and agreed to pay more than $795 million in total fines and penalties to resolve longstanding violations of the Foreign Corrupt Practices Act.

According to the companies’ admissions, VimpelCom and Unitel, through various executives and employees, paid bribes to an Uzbek government official to enter and continue operating in the Uzbek telecommunications market. The companies structured and concealed the bribes through various payments to a shell company that certain VimpelCom and Unitel management knew was beneficially owned by the foreign official. In total, VimpelCom paid more than $114 million in bribery payments between 2006 and 2012.