Ukrainian investigators have identified all participants in the criminal group involved in the killing of former Russian State Duma deputy Denis Voronenkov in central Kyiv and the prosecutors are sending the case to court, Ukraine's Prosecutor General Yuriy Lutsenko said.

"A large-scale investigation has helped to identify all participants in the criminal group, including the masterminds and the perpetrators involved in this murder," the prosecutor general said at a briefing in Kyiv on Monday.

According to him, investigators established that Voronenkov's murder had been ordered and that the reason for the murder was his testimony on the participation of Russian troops in combat operations on Ukrainian territories, now occupied by Russia, in particular, Crimea. Lutsenko said that the murder had been prepared by representatives of the leadership of the Russian Federal Security Service (FSB) and the leaders of criminal groups.

He also said that the prosecutor's office was forwarding the case to court.

Lutsenko confirmed the reports made earlier that this contract killing had been executed by Ukrainian citizens.

Deputy Prosecutor of Kyiv Pavlo Kononenko, in turn, said at the briefing that the weapon for the murder had been sold to the perpetrators by Hennadiy Konev, who was engaged in the trade in mock weapons. At the same time, he noted that the gun from which the ex-deputy had been killed had passed through the lists of a military unit of the Ukrainian Armed Forces in Artemivsk (Donetsk region), where it was purchased by Konev.

Lutsenko added that Konev had the right to legally sell non-combat weapons, namely mock-ups, but he also sold the ones that could be converted into combat weapons.

He recalled that Voronenkov's killer had been shot dead at the scene of the crime, two persons involved in the case - Los and Yaroslav Tarasenko – had been arrested and are in jail; and two more are on the wanted list, particularly Yaroslav Levenets and Yuriy Vasylenko, the leader of a criminal group.

"A notice of suspicion was handed to Yuriy Oleksandrovych Vasylenko, born in 1979, whose location is currently being determined. Yaroslav Anatoliyovych Levenets, born in 1985, was also notified of the suspicion in committing a crime envisaged by Clause 12, Part 2, Article 115 of the Criminal Code Ukraine and placed on the international wanted list," Lutsenko said.

According to him, one of the detainees - Los - was together with Levenets, a co-organizer of the crime. He organized two drivers and a killer, whereas Tarasenko was the driver of a Lanos car, on which the killer arrived, Lutsenko said.

At the same time, according to Lutsenko, the procedural status of Dmitry Tyurin, a son of Vladimir Tyurin, who organized and ordered Voronenkov's murder, "has not currently been determined, it is still necessary to conduct a number of investigative actions." He suggested that he could be incriminated with complicity.

"His prospect is Article 27 or 28 [of the Ukrainian Criminal Code] - complicity in criminal actions," he said.

According to earlier reports, Voronenkov was killed in central Kyiv on March 23. The assassin, Pavlo Parshov, was wounded by the former deputy's security guard and later died at a hospital.

Voronenkov's assassin had an accomplice, Yaroslav Levenets, who has been wanted for economic crimes since 2012. Yaroslav Tarasenko is also a suspect in the crime. He was detained on July 16.