Novaya Gazeta’s journalists claim to have tracked down a colleague of now-retired Colonel Sergei Dubinsky who, according to some reports, was responsible for delivering to the Donbass the Buk missile used to shoot down Malaysian flight MH17.

Dubinsky is supposed to have gone under the pseudonym Khmuriy, which translates to gloomy. Radio conversations between Khmuriy and Buryat were recorded by Ukraine’s Security Service on the day of the wreckage and published in October 2015. The conversations allegedly prove that the airliner was shot down by a Russian Buk missile delivered to the separatist-controlled territory.

Sergei Tiunov, who claims to be Dubinsky’s colleague, confirmed to Novaya Gazeta that the voice on the recording was that of Khmuriy. Tiunov also said that he had communicated with Dubinsky after flight MH17 was shot down and that the two discussed the consequences of the plane crash.

Tiunov, noted the media outlet, is the leader of defense unit Zaporozhye and a veteran of military operations in Afghanistan, where, he claims to have served with Dubinsky.

Tiunov has said that he agreed to talk with Novaya Gazeta out of a desire to protect his friend and colleague, who, in Tiunov’s opinion, was only carrying out an order, but can name those who gave it and, thus, bear responsibility for what happened.

In February 2017, Researchers at Bellingcat announced that they managed to link retired Colonel Sergei Dubinsky to the pseudonym Khmuriy. According to Bellingcat, Dubinsky, who left the Donbass in 2015, lives in the Rostov region.

In correspondence with BBC Russian, Khmuriy categorically rejected the findings, stating that they were “an attempt to lead the investigation away from the fact that the [missiles] were shot conducted from a Ukrainian Buk.” Khmuriy did not disclose his real name in the correspondence.

On July 17, 2014, Malaysian Airlines flight MH17 was shot down over the Donetsk region. All 298 people aboard the airplane died. An international investigation team concluded that the airplane had been hit by a Buk missile which had recently arrived from Russia and was returned shortly thereafter. Russia denies these allegations.