A senior Russian general who was accused in a recent investigation of being a coordinator of separatist forces in eastern Ukraine and of possibly playing a role in the downing of a civilian airliner in July 2014 has said he plans to sue the authors of the report for defamation.

Retired General Nikolai Tkachyov told Novaya Gazeta on December 9 that he will sue the Bellingcat investigative collective and the independent website The Insider over their report, in which they used digital voice analysis to identify Tkachyov as a man codenamed Delfin (dolphin) who appears on intercepted communications with separatist fighters.

Tkachyov denies that he was Delfin or that he was in eastern Ukraine in 2014. He said he has spent the last few years in the Urals city of Yekaterinburg busying himself with the "patriotic education of youths."

Bellingcat and The Insider published their investigation on December 8. In it, they reported that they had enlisted two independent analytical centers -- one in the United States and one in Lithuania -- to compare the intercepted audio from 2014 with recordings of Tkachyov made under the pretext of interviewing him for another story.

The two centers, using various digital analytical methods, independently determined it was "highly probable" that the man on the recordings and Tkachyov were one and the same.

According to the report, Delfin was a Russian general who was based in the Ukrainian town of Krasnodon in the summer of 2014 with the task of coordinating disparate separatist militia units in parts of Ukraine's Donetsk and Luhansk regions.

The Dutch-led Joint Investigative Team (JIT) has identified Delfin as a person of interest in the downing of Malaysia Airlines flight MH17 in July 2014.

The JIT determined in 2016 that it was shot down from separatist-held territory in the Donetsk region by a BUK antiaircraft system provided by the Russian military. The JIT report says the BUK entered Ukraine near Krasnodon and was spirited back into Russia immediately after the airliner was shot down, killing all 298 people aboard.

Russia denies interfering in Ukraine's internal affairs, despite compelling evidence that Moscow has provided military, economic, and political support to separatists fighting against Kyiv. Russia and the separatists deny shooting down MH17 and have offered several other theories to explain the incident, all of which have been rejected by investigators.

Tkachyov, 68, is a decorated veteran of both Russian campaigns in Chechnya. He was released from military service in 2010.

After his retirement, however, he served in 2011-12 as a military adviser to the government of Syria. After his return, he was assigned to the Central Military District and based in Yekaterinburg.

In May 2014, he attended the Victory Day parade in Yekaterinburg. He appeared again in public in August 2014 at an event celebrating Orenburg Cossacks.

With reporting by Novaya Gazeta