Photo from UNIAN

"The terrorist went to temporarily occupied territory, namely the city of Donetsk on March 6. This gives the grounds to the president [of Ukraine Petro Poroshenko] and myself to suspect of Russia's involvement in that case. Ukrainian guardsmen [the assassin was reported to have served in the National Guard of Ukraine], even former ones, are not allowed to visit that territory. We've searched the flat where the killer lived with two other persons. I cannot reveal more details due to the ongoing investigation," Lutsenko told Bild.

As UNIAN reported earlier, former State Duma member Denis Voronenkov, who was expected to become an important witness in a treason trial against Russian-backed ex-president of Ukraine Viktor Yanukovych, was shot dead in the center of Kyiv on March 23, 2017. Voronenkov's bodyguard, who was wounded in the attack, also managed to hit the assassin with several shots as he returned fire. The killer later died amid surgery in a Kyiv hospital.

Voronenkov and his wife, the singer Maria Maksakova, who was also a Russian politician, were granted Ukrainian citizenship in December 2016 after fleeing Russia. A former Communist Party member in the Russian parliament, he feared for his safety after speaking out against Russian President Vladimir Putin.

Voronenkov had been a vocal critic of the Kremlin's actions in Crimea and eastern Ukraine. He told Ukrainian media in an interview that Russia was going through a "pseudo-patriotic frenzy" similar to Nazi Germany.

Read alsoRussia's former MP compares RF with Nazi Germany, calls occupation of Crimea blunderRussia launched a smear campaign against Voronenkov last year, pinning US$ 5 million fraud charges on him and his wife. The Russian Investigative Committee indicted Voronenkov in absentia and put him on the Russian federal wanted list. Voronenkov was accused of large-scale fraud, namely an illegal seizure of a building in the center of Moscow in 2011. The criminal case against him was opened in October 2011.