The former Russian MP Denis Voronenkov has been shot and killed in Kiev.
Police said an unidentified gunman had shot Voronenkov dead at the entrance of an upmarket hotel in the Ukrainian capital.
Voronenkov, 45, a former member of the Communist faction in the lower house of the Russian parliament, had moved to Ukraine last autumn and had been granted Ukrainian citizenship.
He left Russia with his wife, the singer Maria Maksakova, who was also an MP. He said he had to leave the country because the Russian security agencies were persecuting him, and he renounced his Russian citizenship.
Voronenkov gave a number of interviews after his defection that was sharply critical of the Russian president, Vladimir Putin, and Kremlin policy in Ukraine. However, the decision to grant him citizenship after he had taken part in the parliamentary vote to annex Crimea was strongly criticised in Ukraine.
Voronenkov was on his way to meet Ilya Ponomarev, also a former Russian MP who fled the country, when he was shot, according to Ponomarev.
The Premier Palace hotel is in the very centre of Kiev, and is popular with local businessmen and visiting dignitaries.
Ponomarev wrote on Facebook: “I have no words. The security guard was able to injure the attacker. The potential theory is obvious. Voronenko was not a crook, but an investigator who was fatally dangerous to Russian authorities.”
Ukraine’s president, Petro Poroshenko, summoned the head of the security services to brief him on the killing. Ukraine’s prosecutor general, Yuri Lutsenko, wrote on Facebook that the killing was “the usual kind of Kremlin retribution”.