Journalists managed to obtain new data on the involvement of the Russian military officer, Sergei Dubinsky, in the downing of the Malaysian passenger jet flight MH17 in the summer of 2014, killing 298 people on board.

The Joint Investigation Team and Ukrainian law enforcers have not yet named suspects in the terrorist attack on MH17. At the same time, journalists and international research organizations identified at least one of the probe targets. It's Russian Colonel Sergei Dubinsky aka "Khmuryi", RFE/RL's project Donbas.Realii reports.

Radio interceptions by the SBU security service, eyewitness accounts, and conclusions of the JIT - all this helped Donbas.Realii recreate the route of the Russian Buk air defense missile system as it was moved along the militant-controlled territory toward the village of Pervomaisky, where a deadly launch was made.

The investigation report includes intercepted communications between those complicit in the terrorist act. The man who gives instructions on Buk transportation appears on SBU records under the call sign "Khmuryi". Chief of Eurospace NGO Oleh Baturin was one of the first people to identify Khmuryi as Sergei Dubinsky.

"He was, in fact, one of the architects of military management bodies in the 'DPR'. Then, based on these units he had created, he formed the so-called Main Intelligence Directorate of the 'DPR,' which he himself headed," says Oleh Baturin.

Dubinsky was initially the Soviet, and then the Russian military officer, Colonel of the Main Intelligence Directorate of the General Staff of Russia. Baturin adds that he has managed to obtain documents confirming that during the Donbas deployment, Dubinsky remained a Russian serviceman on active duty.

Read alsoBellingcat publishes new photo of Buk 332 from day of MH17 downing"He testified about this in his own appeal to the Southern Military District of Russia where he asked for money to purchase housing as a military serviceman. In the appeal, he laid down his military ID number and service period in the armed forces of the Soviet Union and Russian Federation until December 2014," continues Oleh Baturin.

Journalists also managed to find the brother of Dubinsky, Roman, who allegedly lives in Kyiv. Since the attack on MH17, Roman has never given any interviews. For the first time, he agreed to a frank conversation with reporters.

Roman does not hide the fact that his brother was indeed a Russian military and fought on the side of militants in 2014. "Khmuryi" told him about it personally. "He called me and said that he was 'now in the DPR'."

"I said, 'What are you doing there? What's the point?' I don't get it, fundamentally. I have a different position – it's completely pro-Ukrainian."

Roman had another conversation with his brother after the media reported that "Khmuryi" had been involved in the Buk transportation.

Read alsoMH17 case: Bellingcat spots possible organizer of relocation of deadly Buk (Photo)"When I found out about this plane, I called him too. I had his phone number, but later I deleted it. I called him and asked who did it. He answered me that this was done by the Ukrainian side. That was his answer. I told him that there were some facts, there were some records. He said that they did not do this and that it's a 'provocation'," Roman Dubinsky said.

Journalists also tried to talk directly with Sergei Dubinsky, who now lives on the Bolshoi Log village in Russia's Rostov region. The man refused to talk with journalists. "I don't speak with Radio Liberty or RBC, etc. Because you have an 'interesting' position. Goodbye," he said.

Roman Dubinsky hopes that the investigation will be able to find truth, even if the result shows his brother is guilty.

He repeated the words he had said to "Khmuryi" during their last conversation: "If it's you who shot down the plane - you should be punished for this. And there will be no other option in five, ten, or twenty years. For those 300 people killed, the guilty ones must be punished."